2 * Copyright 2015 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 // @author: Andrei Alexandrescu (aalexandre)
20 #ifndef FOLLY_BASE_FBSTRING_H_
21 #define FOLLY_BASE_FBSTRING_H_
25 #include <type_traits>
27 // This file appears in two locations: inside fbcode and in the
28 // libstdc++ source code (when embedding fbstring as std::string).
29 // To aid in this schizophrenic use, _LIBSTDCXX_FBSTRING is defined in
30 // libstdc++'s c++config.h, to gate use inside fbcode v. libstdc++.
31 #ifdef _LIBSTDCXX_FBSTRING
33 #pragma GCC system_header
35 // Handle the cases where the fbcode version (folly/Malloc.h) is included
36 // either before or after this inclusion.
37 #ifdef FOLLY_MALLOC_H_
38 #undef FOLLY_MALLOC_H_
39 #include "basic_fbstring_malloc.h" // nolint
41 #include "basic_fbstring_malloc.h" // nolint
42 #undef FOLLY_MALLOC_H_
45 #else // !_LIBSTDCXX_FBSTRING
47 #include <folly/Portability.h>
49 // libc++ doesn't provide this header, nor does msvc
50 #ifdef FOLLY_HAVE_BITS_CXXCONFIG_H
51 #include <bits/c++config.h>
59 #include <folly/Traits.h>
60 #include <folly/Malloc.h>
61 #include <folly/Hash.h>
62 #include <folly/ScopeGuard.h>
64 #if FOLLY_HAVE_DEPRECATED_ASSOC
65 #ifdef _GLIBCXX_SYMVER
66 #include <ext/hash_set>
67 #include <ext/hash_map>
73 // We defined these here rather than including Likely.h to avoid
74 // redefinition errors when fbstring is imported into libstdc++.
75 #if defined(__GNUC__) && __GNUC__ >= 4
76 #define FBSTRING_LIKELY(x) (__builtin_expect((x), 1))
77 #define FBSTRING_UNLIKELY(x) (__builtin_expect((x), 0))
79 #define FBSTRING_LIKELY(x) (x)
80 #define FBSTRING_UNLIKELY(x) (x)
83 // Ignore shadowing warnings within this file, so includers can use -Wshadow.
84 #pragma GCC diagnostic push
85 #pragma GCC diagnostic ignored "-Wshadow"
87 // FBString cannot use throw when replacing std::string, though it may still
90 #define throw FOLLY_FBSTRING_MAY_NOT_USE_THROW
92 #ifdef _LIBSTDCXX_FBSTRING
93 namespace std _GLIBCXX_VISIBILITY(default) {
94 _GLIBCXX_BEGIN_NAMESPACE_VERSION
99 // Different versions of gcc/clang support different versions of
100 // the address sanitizer attribute. Unfortunately, this attribute
101 // has issues when inlining is used, so disable that as well.
102 #if defined(__clang__)
103 # if __has_feature(address_sanitizer)
104 # if __has_attribute(__no_address_safety_analysis__)
105 # define FBSTRING_DISABLE_ADDRESS_SANITIZER \
106 __attribute__((__no_address_safety_analysis__, __noinline__))
107 # elif __has_attribute(__no_sanitize_address__)
108 # define FBSTRING_DISABLE_ADDRESS_SANITIZER \
109 __attribute__((__no_sanitize_address__, __noinline__))
112 #elif defined (__GNUC__) && \
114 (__GNUC_MINOR__ >= 8) && \
116 # define FBSTRING_DISABLE_ADDRESS_SANITIZER \
117 __attribute__((__no_address_safety_analysis__, __noinline__))
119 #ifndef FBSTRING_DISABLE_ADDRESS_SANITIZER
120 # define FBSTRING_DISABLE_ADDRESS_SANITIZER
123 namespace fbstring_detail {
125 template <class InIt, class OutIt>
128 typename std::iterator_traits<InIt>::difference_type n,
130 for (; n != 0; --n, ++b, ++d) {
136 template <class Pod, class T>
137 inline void pod_fill(Pod* b, Pod* e, T c) {
138 assert(b && e && b <= e);
139 /*static*/ if (sizeof(T) == 1) {
142 auto const ee = b + ((e - b) & ~7u);
143 for (; b != ee; b += 8) {
154 for (; b != e; ++b) {
161 * Lightly structured memcpy, simplifies copying PODs and introduces
162 * some asserts. Unfortunately using this function may cause
163 * measurable overhead (presumably because it adjusts from a begin/end
164 * convention to a pointer/size convention, so it does some extra
165 * arithmetic even though the caller might have done the inverse
166 * adaptation outside).
169 inline void pod_copy(const Pod* b, const Pod* e, Pod* d) {
171 assert(d >= e || d + (e - b) <= b);
172 memcpy(d, b, (e - b) * sizeof(Pod));
176 * Lightly structured memmove, simplifies copying PODs and introduces
180 inline void pod_move(const Pod* b, const Pod* e, Pod* d) {
182 memmove(d, b, (e - b) * sizeof(*b));
185 } // namespace fbstring_detail
188 * Defines a special acquisition method for constructing fbstring
189 * objects. AcquireMallocatedString means that the user passes a
190 * pointer to a malloc-allocated string that the fbstring object will
193 enum class AcquireMallocatedString {};
196 * fbstring_core_model is a mock-up type that defines all required
197 * signatures of a fbstring core. The fbstring class itself uses such
198 * a core object to implement all of the numerous member functions
199 * required by the standard.
201 * If you want to define a new core, copy the definition below and
202 * implement the primitives. Then plug the core into basic_fbstring as
203 * a template argument.
205 template <class Char>
206 class fbstring_core_model {
208 fbstring_core_model();
209 fbstring_core_model(const fbstring_core_model &);
210 ~fbstring_core_model();
211 // Returns a pointer to string's buffer (currently only contiguous
212 // strings are supported). The pointer is guaranteed to be valid
213 // until the next call to a non-const member function.
214 const Char * data() const;
215 // Much like data(), except the string is prepared to support
216 // character-level changes. This call is a signal for
217 // e.g. reference-counted implementation to fork the data. The
218 // pointer is guaranteed to be valid until the next call to a
219 // non-const member function.
220 Char * mutable_data();
221 // Returns a pointer to string's buffer and guarantees that a
222 // readable '\0' lies right after the buffer. The pointer is
223 // guaranteed to be valid until the next call to a non-const member
225 const Char * c_str() const;
226 // Shrinks the string by delta characters. Asserts that delta <=
228 void shrink(size_t delta);
229 // Expands the string by delta characters (i.e. after this call
230 // size() will report the old size() plus delta) but without
231 // initializing the expanded region. Returns a pointer to the memory
232 // to be initialized (the beginning of the expanded portion). The
233 // caller is expected to fill the expanded area appropriately.
234 Char* expand_noinit(size_t delta);
235 // Expands the string by one character and sets the last character
237 void push_back(Char c);
238 // Returns the string's size.
240 // Returns the string's capacity, i.e. maximum size that the string
241 // can grow to without reallocation. Note that for reference counted
242 // strings that's technically a lie - even assigning characters
243 // within the existing size would cause a reallocation.
244 size_t capacity() const;
245 // Returns true if the data underlying the string is actually shared
246 // across multiple strings (in a refcounted fashion).
247 bool isShared() const;
248 // Makes sure that at least minCapacity characters are available for
249 // the string without reallocation. For reference-counted strings,
250 // it should fork the data even if minCapacity < size().
251 void reserve(size_t minCapacity);
254 fbstring_core_model& operator=(const fbstring_core_model &);
259 * This is the core of the string. The code should work on 32- and
260 * 64-bit and both big- and little-endianan architectures with any
263 * The storage is selected as follows (assuming we store one-byte
264 * characters on a 64-bit machine): (a) "small" strings between 0 and
265 * 23 chars are stored in-situ without allocation (the rightmost byte
266 * stores the size); (b) "medium" strings from 24 through 254 chars
267 * are stored in malloc-allocated memory that is copied eagerly; (c)
268 * "large" strings of 255 chars and above are stored in a similar
269 * structure as medium arrays, except that the string is
270 * reference-counted and copied lazily. the reference count is
271 * allocated right before the character array.
273 * The discriminator between these three strategies sits in two
274 * bits of the rightmost char of the storage. If neither is set, then the
275 * string is small (and its length sits in the lower-order bits on
276 * little-endian or the high-order bits on big-endian of that
277 * rightmost character). If the MSb is set, the string is medium width.
278 * If the second MSb is set, then the string is large. On little-endian,
279 * these 2 bits are the 2 MSbs of MediumLarge::capacity_, while on
280 * big-endian, these 2 bits are the 2 LSbs. This keeps both little-endian
281 * and big-endian fbstring_core equivalent with merely different ops used
282 * to extract capacity/category.
284 template <class Char> class fbstring_core {
286 static constexpr bool kIsLittleEndian =
287 __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__;
288 static constexpr bool kIsBigEndian =
289 __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__;
291 kIsLittleEndian || kIsBigEndian, "unable to identify endianness");
293 fbstring_core() noexcept { reset(); }
295 fbstring_core(const fbstring_core & rhs) {
296 assert(&rhs != this);
297 // Simplest case first: small strings are bitblitted
298 if (rhs.category() == Category::isSmall) {
299 static_assert(offsetof(MediumLarge, data_) == 0,
300 "fbstring layout failure");
301 static_assert(offsetof(MediumLarge, size_) == sizeof(ml_.data_),
302 "fbstring layout failure");
303 static_assert(offsetof(MediumLarge, capacity_) == 2 * sizeof(ml_.data_),
304 "fbstring layout failure");
305 // Just write the whole thing, don't look at details. In
306 // particular we need to copy capacity anyway because we want
307 // to set the size (don't forget that the last character,
308 // which stores a short string's length, is shared with the
309 // ml_.capacity field).
311 assert(category() == Category::isSmall && this->size() == rhs.size());
312 } else if (rhs.category() == Category::isLarge) {
313 // Large strings are just refcounted
315 RefCounted::incrementRefs(ml_.data_);
316 assert(category() == Category::isLarge && size() == rhs.size());
318 // Medium strings are copied eagerly. Don't forget to allocate
319 // one extra Char for the null terminator.
320 auto const allocSize =
321 goodMallocSize((1 + rhs.ml_.size_) * sizeof(Char));
322 ml_.data_ = static_cast<Char*>(checkedMalloc(allocSize));
323 fbstring_detail::pod_copy(rhs.ml_.data_,
325 rhs.ml_.data_ + rhs.ml_.size_ + 1,
327 // No need for writeTerminator() here, we copied one extra
328 // element just above.
329 ml_.size_ = rhs.ml_.size_;
330 ml_.setCapacity(allocSize / sizeof(Char) - 1, Category::isMedium);
331 assert(category() == Category::isMedium);
333 assert(size() == rhs.size());
334 assert(memcmp(data(), rhs.data(), size() * sizeof(Char)) == 0);
337 fbstring_core(fbstring_core&& goner) noexcept {
340 if (goner.category() != Category::isSmall) {
341 // Clean goner's carcass
346 // NOTE(agallagher): The word-aligned copy path copies bytes which are
347 // outside the range of the string, and makes address sanitizer unhappy,
348 // so just disable it on this function.
349 fbstring_core(const Char *const data, const size_t size)
350 FBSTRING_DISABLE_ADDRESS_SANITIZER {
352 #ifndef _LIBSTDCXX_FBSTRING
354 assert(this->size() == size);
355 assert(memcmp(this->data(), data, size * sizeof(Char)) == 0);
360 // Simplest case first: small strings are bitblitted
361 if (size <= maxSmallSize) {
362 // Layout is: Char* data_, size_t size_, size_t capacity_
363 static_assert(sizeof(*this) == sizeof(Char*) + 2 * sizeof(size_t),
364 "fbstring has unexpected size");
365 static_assert(sizeof(Char*) == sizeof(size_t),
366 "fbstring size assumption violation");
367 // sizeof(size_t) must be a power of 2
368 static_assert((sizeof(size_t) & (sizeof(size_t) - 1)) == 0,
369 "fbstring size assumption violation");
371 // If data is aligned, use fast word-wise copying. Otherwise,
372 // use conservative memcpy.
373 if (reinterpret_cast<size_t>(data) & (sizeof(size_t) - 1)) {
374 fbstring_detail::pod_copy(data, data + size, small_);
376 // Copy one word (64 bits) at a time
377 const size_t byteSize = size * sizeof(Char);
378 if (byteSize > 2 * sizeof(size_t)) {
380 ml_.capacity_ = reinterpret_cast<const size_t*>(data)[2];
382 ml_.size_ = reinterpret_cast<const size_t*>(data)[1];
384 ml_.data_ = *reinterpret_cast<Char**>(const_cast<Char*>(data));
385 } else if (byteSize > sizeof(size_t)) {
388 } else if (size > 0) {
395 } else if (size <= maxMediumSize) {
396 // Medium strings are allocated normally. Don't forget to
397 // allocate one extra Char for the terminating null.
398 auto const allocSize = goodMallocSize((1 + size) * sizeof(Char));
399 ml_.data_ = static_cast<Char*>(checkedMalloc(allocSize));
400 fbstring_detail::pod_copy(data, data + size, ml_.data_);
402 ml_.setCapacity(allocSize / sizeof(Char) - 1, Category::isMedium);
404 // Large strings are allocated differently
405 size_t effectiveCapacity = size;
406 auto const newRC = RefCounted::create(data, & effectiveCapacity);
407 ml_.data_ = newRC->data_;
409 ml_.setCapacity(effectiveCapacity, Category::isLarge);
414 ~fbstring_core() noexcept {
415 auto const c = category();
416 if (c == Category::isSmall) {
419 if (c == Category::isMedium) {
423 RefCounted::decrementRefs(ml_.data_);
426 // Snatches a previously mallocated string. The parameter "size"
427 // is the size of the string, and the parameter "allocatedSize"
428 // is the size of the mallocated block. The string must be
429 // \0-terminated, so allocatedSize >= size + 1 and data[size] == '\0'.
431 // So if you want a 2-character string, pass malloc(3) as "data",
432 // pass 2 as "size", and pass 3 as "allocatedSize".
433 fbstring_core(Char * const data,
435 const size_t allocatedSize,
436 AcquireMallocatedString) {
438 assert(allocatedSize >= size + 1);
439 assert(data[size] == '\0');
440 // Use the medium string storage
443 // Don't forget about null terminator
444 ml_.setCapacity(allocatedSize - 1, Category::isMedium);
446 // No need for the memory
452 // swap below doesn't test whether &rhs == this (and instead
453 // potentially does extra work) on the premise that the rarity of
454 // that situation actually makes the check more expensive than is
456 void swap(fbstring_core & rhs) {
462 // In C++11 data() and c_str() are 100% equivalent.
463 const Char * data() const {
467 Char * mutable_data() {
468 auto const c = category();
469 if (c == Category::isSmall) {
472 assert(c == Category::isMedium || c == Category::isLarge);
473 if (c == Category::isLarge && RefCounted::refs(ml_.data_) > 1) {
475 size_t effectiveCapacity = ml_.capacity();
476 auto const newRC = RefCounted::create(& effectiveCapacity);
477 // If this fails, someone placed the wrong capacity in an
479 assert(effectiveCapacity >= ml_.capacity());
480 fbstring_detail::pod_copy(ml_.data_, ml_.data_ + ml_.size_ + 1,
482 RefCounted::decrementRefs(ml_.data_);
483 ml_.data_ = newRC->data_;
484 // No need to call writeTerminator(), we have + 1 above.
489 const Char * c_str() const {
490 auto const c = category();
491 if (c == Category::isSmall) {
492 assert(small_[smallSize()] == '\0');
495 assert(c == Category::isMedium || c == Category::isLarge);
496 assert(ml_.data_[ml_.size_] == '\0');
500 void shrink(const size_t delta) {
501 if (category() == Category::isSmall) {
502 // Check for underflow
503 assert(delta <= smallSize());
504 setSmallSize(smallSize() - delta);
505 } else if (category() == Category::isMedium ||
506 RefCounted::refs(ml_.data_) == 1) {
507 // Medium strings and unique large strings need no special
509 assert(ml_.size_ >= delta);
513 assert(ml_.size_ >= delta);
514 // Shared large string, must make unique. This is because of the
515 // durn terminator must be written, which may trample the shared
518 fbstring_core(ml_.data_, ml_.size_ - delta).swap(*this);
520 // No need to write the terminator.
524 void reserve(size_t minCapacity) {
525 if (category() == Category::isLarge) {
527 if (RefCounted::refs(ml_.data_) > 1) {
528 // We must make it unique regardless; in-place reallocation is
529 // useless if the string is shared. In order to not surprise
530 // people, reserve the new block at current capacity or
531 // more. That way, a string's capacity never shrinks after a
533 minCapacity = std::max(minCapacity, ml_.capacity());
534 auto const newRC = RefCounted::create(& minCapacity);
535 fbstring_detail::pod_copy(ml_.data_, ml_.data_ + ml_.size_ + 1,
537 // Done with the old data. No need to call writeTerminator(),
538 // we have + 1 above.
539 RefCounted::decrementRefs(ml_.data_);
540 ml_.data_ = newRC->data_;
541 ml_.setCapacity(minCapacity, Category::isLarge);
542 // size remains unchanged
544 // String is not shared, so let's try to realloc (if needed)
545 if (minCapacity > ml_.capacity()) {
546 // Asking for more memory
548 RefCounted::reallocate(ml_.data_, ml_.size_,
549 ml_.capacity(), minCapacity);
550 ml_.data_ = newRC->data_;
551 ml_.setCapacity(minCapacity, Category::isLarge);
554 assert(capacity() >= minCapacity);
556 } else if (category() == Category::isMedium) {
557 // String is not shared
558 if (minCapacity <= ml_.capacity()) {
559 return; // nothing to do, there's enough room
561 if (minCapacity <= maxMediumSize) {
562 // Keep the string at medium size. Don't forget to allocate
563 // one extra Char for the terminating null.
564 size_t capacityBytes = goodMallocSize((1 + minCapacity) * sizeof(Char));
565 ml_.data_ = static_cast<Char *>(
568 ml_.size_ * sizeof(Char),
569 (ml_.capacity() + 1) * sizeof(Char),
572 ml_.setCapacity(capacityBytes / sizeof(Char) - 1, Category::isMedium);
574 // Conversion from medium to large string
575 fbstring_core nascent;
576 // Will recurse to another branch of this function
577 nascent.reserve(minCapacity);
578 nascent.ml_.size_ = ml_.size_;
579 fbstring_detail::pod_copy(ml_.data_, ml_.data_ + ml_.size_,
583 assert(capacity() >= minCapacity);
586 assert(category() == Category::isSmall);
587 if (minCapacity > maxMediumSize) {
589 auto const newRC = RefCounted::create(& minCapacity);
590 auto const size = smallSize();
591 fbstring_detail::pod_copy(small_, small_ + size + 1, newRC->data_);
592 // No need for writeTerminator(), we wrote it above with + 1.
593 ml_.data_ = newRC->data_;
595 ml_.setCapacity(minCapacity, Category::isLarge);
596 assert(capacity() >= minCapacity);
597 } else if (minCapacity > maxSmallSize) {
599 // Don't forget to allocate one extra Char for the terminating null
600 auto const allocSizeBytes =
601 goodMallocSize((1 + minCapacity) * sizeof(Char));
602 auto const data = static_cast<Char*>(checkedMalloc(allocSizeBytes));
603 auto const size = smallSize();
604 fbstring_detail::pod_copy(small_, small_ + size + 1, data);
605 // No need for writeTerminator(), we wrote it above with + 1.
608 ml_.setCapacity(allocSizeBytes / sizeof(Char) - 1, Category::isMedium);
611 // Nothing to do, everything stays put
614 assert(capacity() >= minCapacity);
617 Char * expand_noinit(const size_t delta) {
618 // Strategy is simple: make room, then change size
619 assert(capacity() >= size());
621 if (category() == Category::isSmall) {
624 if (newSz <= maxSmallSize) {
631 newSz = ml_.size_ + delta;
632 if (newSz > capacity()) {
636 assert(capacity() >= newSz);
637 // Category can't be small - we took care of that above
638 assert(category() == Category::isMedium || category() == Category::isLarge);
641 assert(size() == newSz);
642 return ml_.data_ + sz;
645 void push_back(Char c) {
646 assert(capacity() >= size());
648 if (category() == Category::isSmall) {
650 if (sz < maxSmallSize) {
652 setSmallSize(sz + 1);
655 reserve(maxSmallSize * 2);
658 if (sz == capacity()) { // always true for isShared()
659 reserve(1 + sz * 3 / 2); // ensures not shared
663 assert(capacity() >= sz + 1);
664 // Category can't be small - we took care of that above
665 assert(category() == Category::isMedium || category() == Category::isLarge);
671 size_t size() const {
672 return category() == Category::isSmall ? smallSize() : ml_.size_;
675 size_t capacity() const {
676 switch (category()) {
677 case Category::isSmall:
679 case Category::isLarge:
680 // For large-sized strings, a multi-referenced chunk has no
681 // available capacity. This is because any attempt to append
682 // data would trigger a new allocation.
683 if (RefCounted::refs(ml_.data_) > 1) return ml_.size_;
686 return ml_.capacity();
689 bool isShared() const {
690 return category() == Category::isLarge && RefCounted::refs(ml_.data_) > 1;
693 void writeTerminator() {
694 if (category() == Category::isSmall) {
695 const auto s = smallSize();
696 if (s != maxSmallSize) {
700 ml_.data_[ml_.size_] = '\0';
706 fbstring_core & operator=(const fbstring_core & rhs);
708 // Equivalent to setSmallSize(0), but with specialized
709 // writeTerminator which doesn't re-check the category after
710 // capacity_ is overwritten.
712 // Only initialize the tag, will set the MSBs (i.e. the small
713 // string size) to zero too.
714 ml_.capacity_ = kIsLittleEndian
715 ? maxSmallSize << (8 * (sizeof(size_t) - sizeof(Char)))
718 assert(category() == Category::isSmall && size() == 0);
722 std::atomic<size_t> refCount_;
725 static RefCounted * fromData(Char * p) {
726 return static_cast<RefCounted*>(
728 static_cast<unsigned char*>(static_cast<void*>(p))
729 - sizeof(refCount_)));
732 static size_t refs(Char * p) {
733 return fromData(p)->refCount_.load(std::memory_order_acquire);
736 static void incrementRefs(Char * p) {
737 fromData(p)->refCount_.fetch_add(1, std::memory_order_acq_rel);
740 static void decrementRefs(Char * p) {
741 auto const dis = fromData(p);
742 size_t oldcnt = dis->refCount_.fetch_sub(1, std::memory_order_acq_rel);
749 static RefCounted * create(size_t * size) {
750 // Don't forget to allocate one extra Char for the terminating
751 // null. In this case, however, one Char is already part of the
753 const size_t allocSize = goodMallocSize(
754 sizeof(RefCounted) + *size * sizeof(Char));
755 auto result = static_cast<RefCounted*>(checkedMalloc(allocSize));
756 result->refCount_.store(1, std::memory_order_release);
757 *size = (allocSize - sizeof(RefCounted)) / sizeof(Char);
761 static RefCounted * create(const Char * data, size_t * size) {
762 const size_t effectiveSize = *size;
763 auto result = create(size);
764 fbstring_detail::pod_copy(data, data + effectiveSize, result->data_);
768 static RefCounted * reallocate(Char *const data,
769 const size_t currentSize,
770 const size_t currentCapacity,
771 const size_t newCapacity) {
772 assert(newCapacity > 0 && newCapacity > currentSize);
773 auto const dis = fromData(data);
774 assert(dis->refCount_.load(std::memory_order_acquire) == 1);
775 // Don't forget to allocate one extra Char for the terminating
776 // null. In this case, however, one Char is already part of the
778 auto result = static_cast<RefCounted*>(
780 sizeof(RefCounted) + currentSize * sizeof(Char),
781 sizeof(RefCounted) + currentCapacity * sizeof(Char),
782 sizeof(RefCounted) + newCapacity * sizeof(Char)));
783 assert(result->refCount_.load(std::memory_order_acquire) == 1);
788 typedef std::conditional<sizeof(size_t) == 4, uint32_t, uint64_t>::type
791 enum class Category : category_type {
793 isMedium = kIsLittleEndian
794 ? sizeof(size_t) == 4 ? 0x80000000 : 0x8000000000000000
796 isLarge = kIsLittleEndian
797 ? sizeof(size_t) == 4 ? 0x40000000 : 0x4000000000000000
801 Category category() const {
802 // works for both big-endian and little-endian
803 return static_cast<Category>(ml_.capacity_ & categoryExtractMask);
811 size_t capacity() const {
812 return kIsLittleEndian
813 ? capacity_ & capacityExtractMask
817 void setCapacity(size_t cap, Category cat) {
818 capacity_ = kIsLittleEndian
819 ? cap | static_cast<category_type>(cat)
820 : (cap << 2) | static_cast<category_type>(cat);
825 Char small_[sizeof(MediumLarge) / sizeof(Char)];
830 lastChar = sizeof(MediumLarge) - 1,
831 maxSmallSize = lastChar / sizeof(Char),
832 maxMediumSize = 254 / sizeof(Char), // coincides with the small
833 // bin size in dlmalloc
834 categoryExtractMask = kIsLittleEndian
835 ? sizeof(size_t) == 4 ? 0xC0000000 : 0xC000000000000000
837 capacityExtractMask = kIsLittleEndian
838 ? ~categoryExtractMask
841 static_assert(!(sizeof(MediumLarge) % sizeof(Char)),
842 "Corrupt memory layout for fbstring.");
844 size_t smallSize() const {
845 assert(category() == Category::isSmall);
846 auto shift = kIsLittleEndian ? 0 : 2;
847 auto smallShifted = static_cast<size_t>(small_[maxSmallSize]) >> shift;
848 assert(static_cast<size_t>(maxSmallSize) >= smallShifted);
849 return static_cast<size_t>(maxSmallSize) - smallShifted;
852 void setSmallSize(size_t s) {
853 // Warning: this should work with uninitialized strings too,
854 // so don't assume anything about the previous value of
855 // small_[maxSmallSize].
856 assert(s <= maxSmallSize);
857 small_[maxSmallSize] = kIsLittleEndian
859 : (maxSmallSize - s) << 2;
864 #ifndef _LIBSTDCXX_FBSTRING
866 * Dummy fbstring core that uses an actual std::string. This doesn't
867 * make any sense - it's just for testing purposes.
869 template <class Char>
870 class dummy_fbstring_core {
872 dummy_fbstring_core() {
874 dummy_fbstring_core(const dummy_fbstring_core& another)
875 : backend_(another.backend_) {
877 dummy_fbstring_core(const Char * s, size_t n)
880 void swap(dummy_fbstring_core & rhs) {
881 backend_.swap(rhs.backend_);
883 const Char * data() const {
884 return backend_.data();
886 Char * mutable_data() {
887 //assert(!backend_.empty());
888 return &*backend_.begin();
890 void shrink(size_t delta) {
891 assert(delta <= size());
892 backend_.resize(size() - delta);
894 Char * expand_noinit(size_t delta) {
895 auto const sz = size();
896 backend_.resize(size() + delta);
897 return backend_.data() + sz;
899 void push_back(Char c) {
900 backend_.push_back(c);
902 size_t size() const {
903 return backend_.size();
905 size_t capacity() const {
906 return backend_.capacity();
908 bool isShared() const {
911 void reserve(size_t minCapacity) {
912 backend_.reserve(minCapacity);
916 std::basic_string<Char> backend_;
918 #endif // !_LIBSTDCXX_FBSTRING
921 * This is the basic_string replacement. For conformity,
922 * basic_fbstring takes the same template parameters, plus the last
923 * one which is the core.
925 #ifdef _LIBSTDCXX_FBSTRING
926 template <typename E, class T, class A, class Storage>
928 template <typename E,
929 class T = std::char_traits<E>,
930 class A = std::allocator<E>,
931 class Storage = fbstring_core<E> >
933 class basic_fbstring {
937 void (*throw_exc)(const char*),
939 if (!condition) throw_exc(msg);
942 bool isSane() const {
945 empty() == (size() == 0) &&
946 empty() == (begin() == end()) &&
947 size() <= max_size() &&
948 capacity() <= max_size() &&
949 size() <= capacity() &&
950 begin()[size()] == '\0';
954 friend struct Invariant;
957 explicit Invariant(const basic_fbstring& s) : s_(s) {
964 const basic_fbstring& s_;
966 explicit Invariant(const basic_fbstring&) {}
968 Invariant& operator=(const Invariant&);
973 typedef T traits_type;
974 typedef typename traits_type::char_type value_type;
975 typedef A allocator_type;
976 typedef typename A::size_type size_type;
977 typedef typename A::difference_type difference_type;
979 typedef typename A::reference reference;
980 typedef typename A::const_reference const_reference;
981 typedef typename A::pointer pointer;
982 typedef typename A::const_pointer const_pointer;
985 typedef const E* const_iterator;
986 typedef std::reverse_iterator<iterator
987 #ifdef NO_ITERATOR_TRAITS
991 typedef std::reverse_iterator<const_iterator
992 #ifdef NO_ITERATOR_TRAITS
995 > const_reverse_iterator;
997 static const size_type npos; // = size_type(-1)
1000 static void procrustes(size_type& n, size_type nmax) {
1001 if (n > nmax) n = nmax;
1005 // C++11 21.4.2 construct/copy/destroy
1006 explicit basic_fbstring(const A& /*a*/ = A()) noexcept {
1009 basic_fbstring(const basic_fbstring& str)
1010 : store_(str.store_) {
1014 basic_fbstring(basic_fbstring&& goner) noexcept
1015 : store_(std::move(goner.store_)) {
1018 #ifndef _LIBSTDCXX_FBSTRING
1019 // This is defined for compatibility with std::string
1020 /* implicit */ basic_fbstring(const std::string& str)
1021 : store_(str.data(), str.size()) {
1025 basic_fbstring(const basic_fbstring& str, size_type pos,
1026 size_type n = npos, const A& a = A()) {
1027 assign(str, pos, n);
1030 /* implicit */ basic_fbstring(const value_type* s, const A& /*a*/ = A())
1032 ? traits_type::length(s)
1033 : (std::__throw_logic_error(
1034 "basic_fbstring: null pointer initializer not valid"),
1038 basic_fbstring(const value_type* s, size_type n, const A& /*a*/ = A())
1042 basic_fbstring(size_type n, value_type c, const A& /*a*/ = A()) {
1043 auto const data = store_.expand_noinit(n);
1044 fbstring_detail::pod_fill(data, data + n, c);
1045 store_.writeTerminator();
1048 template <class InIt>
1049 basic_fbstring(InIt begin, InIt end,
1050 typename std::enable_if<
1051 !std::is_same<typename std::remove_const<InIt>::type,
1052 value_type*>::value, const A>::type & /*a*/ = A()) {
1056 // Specialization for const char*, const char*
1057 basic_fbstring(const value_type* b, const value_type* e)
1058 : store_(b, e - b) {
1061 // Nonstandard constructor
1062 basic_fbstring(value_type *s, size_type n, size_type c,
1063 AcquireMallocatedString a)
1064 : store_(s, n, c, a) {
1067 // Construction from initialization list
1068 basic_fbstring(std::initializer_list<value_type> il) {
1069 assign(il.begin(), il.end());
1072 ~basic_fbstring() noexcept {
1075 basic_fbstring& operator=(const basic_fbstring& lhs) {
1076 if (FBSTRING_UNLIKELY(&lhs == this)) {
1079 auto const oldSize = size();
1080 auto const srcSize = lhs.size();
1081 if (capacity() >= srcSize && !store_.isShared()) {
1082 // great, just copy the contents
1083 if (oldSize < srcSize)
1084 store_.expand_noinit(srcSize - oldSize);
1086 store_.shrink(oldSize - srcSize);
1087 assert(size() == srcSize);
1088 fbstring_detail::pod_copy(lhs.begin(), lhs.end(), begin());
1089 store_.writeTerminator();
1091 // need to reallocate, so we may as well create a brand new string
1092 basic_fbstring(lhs).swap(*this);
1098 basic_fbstring& operator=(basic_fbstring&& goner) noexcept {
1099 if (FBSTRING_UNLIKELY(&goner == this)) {
1100 // Compatibility with std::basic_string<>,
1101 // C++11 21.4.2 [string.cons] / 23 requires self-move-assignment support.
1104 // No need of this anymore
1105 this->~basic_fbstring();
1106 // Move the goner into this
1107 new(&store_) fbstring_core<E>(std::move(goner.store_));
1111 #ifndef _LIBSTDCXX_FBSTRING
1112 // Compatibility with std::string
1113 basic_fbstring & operator=(const std::string & rhs) {
1114 return assign(rhs.data(), rhs.size());
1117 // Compatibility with std::string
1118 std::string toStdString() const {
1119 return std::string(data(), size());
1122 // A lot of code in fbcode still uses this method, so keep it here for now.
1123 const basic_fbstring& toStdString() const {
1128 basic_fbstring& operator=(const value_type* s) {
1132 basic_fbstring& operator=(value_type c) {
1134 store_.expand_noinit(1);
1135 } else if (store_.isShared()) {
1136 basic_fbstring(1, c).swap(*this);
1139 store_.shrink(size() - 1);
1141 *store_.mutable_data() = c;
1142 store_.writeTerminator();
1146 basic_fbstring& operator=(std::initializer_list<value_type> il) {
1147 return assign(il.begin(), il.end());
1150 // C++11 21.4.3 iterators:
1151 iterator begin() { return store_.mutable_data(); }
1153 const_iterator begin() const { return store_.data(); }
1155 const_iterator cbegin() const { return begin(); }
1158 return store_.mutable_data() + store_.size();
1161 const_iterator end() const {
1162 return store_.data() + store_.size();
1165 const_iterator cend() const { return end(); }
1167 reverse_iterator rbegin() {
1168 return reverse_iterator(end());
1171 const_reverse_iterator rbegin() const {
1172 return const_reverse_iterator(end());
1175 const_reverse_iterator crbegin() const { return rbegin(); }
1177 reverse_iterator rend() {
1178 return reverse_iterator(begin());
1181 const_reverse_iterator rend() const {
1182 return const_reverse_iterator(begin());
1185 const_reverse_iterator crend() const { return rend(); }
1188 // C++11 21.4.5, element access:
1189 const value_type& front() const { return *begin(); }
1190 const value_type& back() const {
1192 // Should be begin()[size() - 1], but that branches twice
1193 return *(end() - 1);
1195 value_type& front() { return *begin(); }
1196 value_type& back() {
1198 // Should be begin()[size() - 1], but that branches twice
1199 return *(end() - 1);
1206 // C++11 21.4.4 capacity:
1207 size_type size() const { return store_.size(); }
1209 size_type length() const { return size(); }
1211 size_type max_size() const {
1212 return std::numeric_limits<size_type>::max();
1215 void resize(const size_type n, const value_type c = value_type()) {
1216 auto size = this->size();
1218 store_.shrink(size - n);
1220 // Do this in two steps to minimize slack memory copied (see
1222 auto const capacity = this->capacity();
1223 assert(capacity >= size);
1224 if (size < capacity) {
1225 auto delta = std::min(n, capacity) - size;
1226 store_.expand_noinit(delta);
1227 fbstring_detail::pod_fill(begin() + size, end(), c);
1230 store_.writeTerminator();
1235 auto const delta = n - size;
1236 store_.expand_noinit(delta);
1237 fbstring_detail::pod_fill(end() - delta, end(), c);
1238 store_.writeTerminator();
1240 assert(this->size() == n);
1243 size_type capacity() const { return store_.capacity(); }
1245 void reserve(size_type res_arg = 0) {
1246 enforce(res_arg <= max_size(), std::__throw_length_error, "");
1247 store_.reserve(res_arg);
1250 void shrink_to_fit() {
1251 // Shrink only if slack memory is sufficiently large
1252 if (capacity() < size() * 3 / 2) {
1255 basic_fbstring(cbegin(), cend()).swap(*this);
1258 void clear() { resize(0); }
1260 bool empty() const { return size() == 0; }
1262 // C++11 21.4.5 element access:
1263 const_reference operator[](size_type pos) const {
1264 return *(begin() + pos);
1267 reference operator[](size_type pos) {
1268 return *(begin() + pos);
1271 const_reference at(size_type n) const {
1272 enforce(n <= size(), std::__throw_out_of_range, "");
1276 reference at(size_type n) {
1277 enforce(n < size(), std::__throw_out_of_range, "");
1281 // C++11 21.4.6 modifiers:
1282 basic_fbstring& operator+=(const basic_fbstring& str) {
1286 basic_fbstring& operator+=(const value_type* s) {
1290 basic_fbstring& operator+=(const value_type c) {
1295 basic_fbstring& operator+=(std::initializer_list<value_type> il) {
1300 basic_fbstring& append(const basic_fbstring& str) {
1302 auto desiredSize = size() + str.size();
1304 append(str.data(), str.size());
1305 assert(size() == desiredSize);
1309 basic_fbstring& append(const basic_fbstring& str, const size_type pos,
1311 const size_type sz = str.size();
1312 enforce(pos <= sz, std::__throw_out_of_range, "");
1313 procrustes(n, sz - pos);
1314 return append(str.data() + pos, n);
1317 basic_fbstring& append(const value_type* s, size_type n) {
1319 Invariant checker(*this);
1322 if (FBSTRING_UNLIKELY(!n)) {
1323 // Unlikely but must be done
1326 auto const oldSize = size();
1327 auto const oldData = data();
1328 // Check for aliasing (rare). We could use "<=" here but in theory
1329 // those do not work for pointers unless the pointers point to
1330 // elements in the same array. For that reason we use
1331 // std::less_equal, which is guaranteed to offer a total order
1332 // over pointers. See discussion at http://goo.gl/Cy2ya for more
1334 std::less_equal<const value_type*> le;
1335 if (FBSTRING_UNLIKELY(le(oldData, s) && !le(oldData + oldSize, s))) {
1336 assert(le(s + n, oldData + oldSize));
1337 const size_type offset = s - oldData;
1338 store_.reserve(oldSize + n);
1339 // Restore the source
1340 s = data() + offset;
1342 // Warning! Repeated appends with short strings may actually incur
1343 // practically quadratic performance. Avoid that by pushing back
1344 // the first character (which ensures exponential growth) and then
1345 // appending the rest normally. Worst case the append may incur a
1346 // second allocation but that will be rare.
1349 memcpy(store_.expand_noinit(n), s, n * sizeof(value_type));
1350 assert(size() == oldSize + n + 1);
1354 basic_fbstring& append(const value_type* s) {
1355 return append(s, traits_type::length(s));
1358 basic_fbstring& append(size_type n, value_type c) {
1359 resize(size() + n, c);
1363 template<class InputIterator>
1364 basic_fbstring& append(InputIterator first, InputIterator last) {
1365 insert(end(), first, last);
1369 basic_fbstring& append(std::initializer_list<value_type> il) {
1370 return append(il.begin(), il.end());
1373 void push_back(const value_type c) { // primitive
1374 store_.push_back(c);
1377 basic_fbstring& assign(const basic_fbstring& str) {
1378 if (&str == this) return *this;
1379 return assign(str.data(), str.size());
1382 basic_fbstring& assign(basic_fbstring&& str) {
1383 return *this = std::move(str);
1386 basic_fbstring& assign(const basic_fbstring& str, const size_type pos,
1388 const size_type sz = str.size();
1389 enforce(pos <= sz, std::__throw_out_of_range, "");
1390 procrustes(n, sz - pos);
1391 return assign(str.data() + pos, n);
1394 basic_fbstring& assign(const value_type* s, const size_type n) {
1395 Invariant checker(*this);
1398 std::copy(s, s + n, begin());
1400 assert(size() == n);
1402 const value_type *const s2 = s + size();
1403 std::copy(s, s2, begin());
1404 append(s2, n - size());
1405 assert(size() == n);
1407 store_.writeTerminator();
1408 assert(size() == n);
1412 basic_fbstring& assign(const value_type* s) {
1413 return assign(s, traits_type::length(s));
1416 basic_fbstring& assign(std::initializer_list<value_type> il) {
1417 return assign(il.begin(), il.end());
1420 template <class ItOrLength, class ItOrChar>
1421 basic_fbstring& assign(ItOrLength first_or_n, ItOrChar last_or_c) {
1422 return replace(begin(), end(), first_or_n, last_or_c);
1425 basic_fbstring& insert(size_type pos1, const basic_fbstring& str) {
1426 return insert(pos1, str.data(), str.size());
1429 basic_fbstring& insert(size_type pos1, const basic_fbstring& str,
1430 size_type pos2, size_type n) {
1431 enforce(pos2 <= str.length(), std::__throw_out_of_range, "");
1432 procrustes(n, str.length() - pos2);
1433 return insert(pos1, str.data() + pos2, n);
1436 basic_fbstring& insert(size_type pos, const value_type* s, size_type n) {
1437 enforce(pos <= length(), std::__throw_out_of_range, "");
1438 insert(begin() + pos, s, s + n);
1442 basic_fbstring& insert(size_type pos, const value_type* s) {
1443 return insert(pos, s, traits_type::length(s));
1446 basic_fbstring& insert(size_type pos, size_type n, value_type c) {
1447 enforce(pos <= length(), std::__throw_out_of_range, "");
1448 insert(begin() + pos, n, c);
1452 iterator insert(const_iterator p, const value_type c) {
1453 const size_type pos = p - begin();
1455 return begin() + pos;
1459 template <int i> class Selector {};
1461 iterator insertImplDiscr(const_iterator p,
1462 size_type n, value_type c, Selector<1>) {
1463 Invariant checker(*this);
1465 auto const pos = p - begin();
1466 assert(p >= begin() && p <= end());
1467 if (capacity() - size() < n) {
1468 const size_type sz = p - begin();
1469 reserve(size() + n);
1472 const iterator oldEnd = end();
1473 if (n < size_type(oldEnd - p)) {
1474 append(oldEnd - n, oldEnd);
1476 // reverse_iterator(oldEnd - n),
1477 // reverse_iterator(p),
1478 // reverse_iterator(oldEnd));
1479 fbstring_detail::pod_move(&*p, &*oldEnd - n,
1481 std::fill(begin() + pos, begin() + pos + n, c);
1483 append(n - (end() - p), c);
1484 append(iterator(p), oldEnd);
1485 std::fill(iterator(p), oldEnd, c);
1487 store_.writeTerminator();
1488 return begin() + pos;
1491 template<class InputIter>
1492 iterator insertImplDiscr(const_iterator i,
1493 InputIter b, InputIter e, Selector<0>) {
1494 return insertImpl(i, b, e,
1495 typename std::iterator_traits<InputIter>::iterator_category());
1498 template <class FwdIterator>
1499 iterator insertImpl(const_iterator i,
1500 FwdIterator s1, FwdIterator s2, std::forward_iterator_tag) {
1501 Invariant checker(*this);
1503 const size_type pos = i - begin();
1504 const typename std::iterator_traits<FwdIterator>::difference_type n2 =
1505 std::distance(s1, s2);
1507 using namespace fbstring_detail;
1508 assert(pos <= size());
1510 const typename std::iterator_traits<FwdIterator>::difference_type maxn2 =
1511 capacity() - size();
1513 // realloc the string
1514 reserve(size() + n2);
1517 if (pos + n2 <= size()) {
1518 const iterator tailBegin = end() - n2;
1519 store_.expand_noinit(n2);
1520 fbstring_detail::pod_copy(tailBegin, tailBegin + n2, end() - n2);
1521 std::copy(const_reverse_iterator(tailBegin), const_reverse_iterator(i),
1522 reverse_iterator(tailBegin + n2));
1523 std::copy(s1, s2, begin() + pos);
1526 const size_type old_size = size();
1527 std::advance(t, old_size - pos);
1528 const size_t newElems = std::distance(t, s2);
1529 store_.expand_noinit(n2);
1530 std::copy(t, s2, begin() + old_size);
1531 fbstring_detail::pod_copy(data() + pos, data() + old_size,
1532 begin() + old_size + newElems);
1533 std::copy(s1, t, begin() + pos);
1535 store_.writeTerminator();
1536 return begin() + pos;
1539 template <class InputIterator>
1540 iterator insertImpl(const_iterator i,
1541 InputIterator b, InputIterator e,
1542 std::input_iterator_tag) {
1543 const auto pos = i - begin();
1544 basic_fbstring temp(begin(), i);
1545 for (; b != e; ++b) {
1548 temp.append(i, cend());
1550 return begin() + pos;
1554 template <class ItOrLength, class ItOrChar>
1555 iterator insert(const_iterator p, ItOrLength first_or_n, ItOrChar last_or_c) {
1556 Selector<std::numeric_limits<ItOrLength>::is_specialized> sel;
1557 return insertImplDiscr(p, first_or_n, last_or_c, sel);
1560 iterator insert(const_iterator p, std::initializer_list<value_type> il) {
1561 return insert(p, il.begin(), il.end());
1564 basic_fbstring& erase(size_type pos = 0, size_type n = npos) {
1565 Invariant checker(*this);
1567 enforce(pos <= length(), std::__throw_out_of_range, "");
1568 procrustes(n, length() - pos);
1569 std::copy(begin() + pos + n, end(), begin() + pos);
1570 resize(length() - n);
1574 iterator erase(iterator position) {
1575 const size_type pos(position - begin());
1576 enforce(pos <= size(), std::__throw_out_of_range, "");
1578 return begin() + pos;
1581 iterator erase(iterator first, iterator last) {
1582 const size_type pos(first - begin());
1583 erase(pos, last - first);
1584 return begin() + pos;
1587 // Replaces at most n1 chars of *this, starting with pos1 with the
1589 basic_fbstring& replace(size_type pos1, size_type n1,
1590 const basic_fbstring& str) {
1591 return replace(pos1, n1, str.data(), str.size());
1594 // Replaces at most n1 chars of *this, starting with pos1,
1595 // with at most n2 chars of str starting with pos2
1596 basic_fbstring& replace(size_type pos1, size_type n1,
1597 const basic_fbstring& str,
1598 size_type pos2, size_type n2) {
1599 enforce(pos2 <= str.length(), std::__throw_out_of_range, "");
1600 return replace(pos1, n1, str.data() + pos2,
1601 std::min(n2, str.size() - pos2));
1604 // Replaces at most n1 chars of *this, starting with pos, with chars from s
1605 basic_fbstring& replace(size_type pos, size_type n1, const value_type* s) {
1606 return replace(pos, n1, s, traits_type::length(s));
1609 // Replaces at most n1 chars of *this, starting with pos, with n2
1612 // consolidated with
1614 // Replaces at most n1 chars of *this, starting with pos, with at
1615 // most n2 chars of str. str must have at least n2 chars.
1616 template <class StrOrLength, class NumOrChar>
1617 basic_fbstring& replace(size_type pos, size_type n1,
1618 StrOrLength s_or_n2, NumOrChar n_or_c) {
1619 Invariant checker(*this);
1621 enforce(pos <= size(), std::__throw_out_of_range, "");
1622 procrustes(n1, length() - pos);
1623 const iterator b = begin() + pos;
1624 return replace(b, b + n1, s_or_n2, n_or_c);
1627 basic_fbstring& replace(iterator i1, iterator i2, const basic_fbstring& str) {
1628 return replace(i1, i2, str.data(), str.length());
1631 basic_fbstring& replace(iterator i1, iterator i2, const value_type* s) {
1632 return replace(i1, i2, s, traits_type::length(s));
1636 basic_fbstring& replaceImplDiscr(iterator i1, iterator i2,
1637 const value_type* s, size_type n,
1640 assert(begin() <= i1 && i1 <= end());
1641 assert(begin() <= i2 && i2 <= end());
1642 return replace(i1, i2, s, s + n);
1645 basic_fbstring& replaceImplDiscr(iterator i1, iterator i2,
1646 size_type n2, value_type c, Selector<1>) {
1647 const size_type n1 = i2 - i1;
1649 std::fill(i1, i1 + n2, c);
1652 std::fill(i1, i2, c);
1653 insert(i2, n2 - n1, c);
1659 template <class InputIter>
1660 basic_fbstring& replaceImplDiscr(iterator i1, iterator i2,
1661 InputIter b, InputIter e,
1663 replaceImpl(i1, i2, b, e,
1664 typename std::iterator_traits<InputIter>::iterator_category());
1669 template <class FwdIterator>
1670 bool replaceAliased(iterator i1, iterator i2,
1671 FwdIterator s1, FwdIterator s2, std::false_type) {
1675 template <class FwdIterator>
1676 bool replaceAliased(iterator i1, iterator i2,
1677 FwdIterator s1, FwdIterator s2, std::true_type) {
1678 static const std::less_equal<const value_type*> le =
1679 std::less_equal<const value_type*>();
1680 const bool aliased = le(&*begin(), &*s1) && le(&*s1, &*end());
1684 // Aliased replace, copy to new string
1685 basic_fbstring temp;
1686 temp.reserve(size() - (i2 - i1) + std::distance(s1, s2));
1687 temp.append(begin(), i1).append(s1, s2).append(i2, end());
1692 template <class FwdIterator>
1693 void replaceImpl(iterator i1, iterator i2,
1694 FwdIterator s1, FwdIterator s2, std::forward_iterator_tag) {
1695 Invariant checker(*this);
1698 // Handle aliased replace
1699 if (replaceAliased(i1, i2, s1, s2,
1700 std::integral_constant<bool,
1701 std::is_same<FwdIterator, iterator>::value ||
1702 std::is_same<FwdIterator, const_iterator>::value>())) {
1706 auto const n1 = i2 - i1;
1708 auto const n2 = std::distance(s1, s2);
1713 std::copy(s1, s2, i1);
1717 fbstring_detail::copy_n(s1, n1, i1);
1718 std::advance(s1, n1);
1724 template <class InputIterator>
1725 void replaceImpl(iterator i1, iterator i2,
1726 InputIterator b, InputIterator e, std::input_iterator_tag) {
1727 basic_fbstring temp(begin(), i1);
1728 temp.append(b, e).append(i2, end());
1733 template <class T1, class T2>
1734 basic_fbstring& replace(iterator i1, iterator i2,
1735 T1 first_or_n_or_s, T2 last_or_c_or_n) {
1737 num1 = std::numeric_limits<T1>::is_specialized,
1738 num2 = std::numeric_limits<T2>::is_specialized;
1739 return replaceImplDiscr(
1740 i1, i2, first_or_n_or_s, last_or_c_or_n,
1741 Selector<num1 ? (num2 ? 1 : -1) : (num2 ? 2 : 0)>());
1744 size_type copy(value_type* s, size_type n, size_type pos = 0) const {
1745 enforce(pos <= size(), std::__throw_out_of_range, "");
1746 procrustes(n, size() - pos);
1748 fbstring_detail::pod_copy(
1755 void swap(basic_fbstring& rhs) {
1756 store_.swap(rhs.store_);
1759 const value_type* c_str() const {
1760 return store_.c_str();
1763 const value_type* data() const { return c_str(); }
1765 allocator_type get_allocator() const {
1766 return allocator_type();
1769 size_type find(const basic_fbstring& str, size_type pos = 0) const {
1770 return find(str.data(), pos, str.length());
1773 size_type find(const value_type* needle, const size_type pos,
1774 const size_type nsize) const {
1775 if (!nsize) return pos;
1776 auto const size = this->size();
1777 // nsize + pos can overflow (eg pos == npos), guard against that by checking
1778 // that nsize + pos does not wrap around.
1779 if (nsize + pos > size || nsize + pos < pos) return npos;
1780 // Don't use std::search, use a Boyer-Moore-like trick by comparing
1781 // the last characters first
1782 auto const haystack = data();
1783 auto const nsize_1 = nsize - 1;
1784 auto const lastNeedle = needle[nsize_1];
1786 // Boyer-Moore skip value for the last char in the needle. Zero is
1787 // not a valid value; skip will be computed the first time it's
1791 const E * i = haystack + pos;
1792 auto iEnd = haystack + size - nsize_1;
1795 // Boyer-Moore: match the last element in the needle
1796 while (i[nsize_1] != lastNeedle) {
1802 // Here we know that the last char matches
1803 // Continue in pedestrian mode
1804 for (size_t j = 0; ; ) {
1806 if (i[j] != needle[j]) {
1807 // Not found, we can skip
1808 // Compute the skip value lazily
1811 while (skip <= nsize_1 && needle[nsize_1 - skip] != lastNeedle) {
1818 // Check if done searching
1821 return i - haystack;
1828 size_type find(const value_type* s, size_type pos = 0) const {
1829 return find(s, pos, traits_type::length(s));
1832 size_type find (value_type c, size_type pos = 0) const {
1833 return find(&c, pos, 1);
1836 size_type rfind(const basic_fbstring& str, size_type pos = npos) const {
1837 return rfind(str.data(), pos, str.length());
1840 size_type rfind(const value_type* s, size_type pos, size_type n) const {
1841 if (n > length()) return npos;
1842 pos = std::min(pos, length() - n);
1843 if (n == 0) return pos;
1845 const_iterator i(begin() + pos);
1847 if (traits_type::eq(*i, *s)
1848 && traits_type::compare(&*i, s, n) == 0) {
1851 if (i == begin()) break;
1856 size_type rfind(const value_type* s, size_type pos = npos) const {
1857 return rfind(s, pos, traits_type::length(s));
1860 size_type rfind(value_type c, size_type pos = npos) const {
1861 return rfind(&c, pos, 1);
1864 size_type find_first_of(const basic_fbstring& str, size_type pos = 0) const {
1865 return find_first_of(str.data(), pos, str.length());
1868 size_type find_first_of(const value_type* s,
1869 size_type pos, size_type n) const {
1870 if (pos > length() || n == 0) return npos;
1871 const_iterator i(begin() + pos),
1873 for (; i != finish; ++i) {
1874 if (traits_type::find(s, n, *i) != 0) {
1881 size_type find_first_of(const value_type* s, size_type pos = 0) const {
1882 return find_first_of(s, pos, traits_type::length(s));
1885 size_type find_first_of(value_type c, size_type pos = 0) const {
1886 return find_first_of(&c, pos, 1);
1889 size_type find_last_of (const basic_fbstring& str,
1890 size_type pos = npos) const {
1891 return find_last_of(str.data(), pos, str.length());
1894 size_type find_last_of (const value_type* s, size_type pos,
1895 size_type n) const {
1896 if (!empty() && n > 0) {
1897 pos = std::min(pos, length() - 1);
1898 const_iterator i(begin() + pos);
1900 if (traits_type::find(s, n, *i) != 0) {
1903 if (i == begin()) break;
1909 size_type find_last_of (const value_type* s,
1910 size_type pos = npos) const {
1911 return find_last_of(s, pos, traits_type::length(s));
1914 size_type find_last_of (value_type c, size_type pos = npos) const {
1915 return find_last_of(&c, pos, 1);
1918 size_type find_first_not_of(const basic_fbstring& str,
1919 size_type pos = 0) const {
1920 return find_first_not_of(str.data(), pos, str.size());
1923 size_type find_first_not_of(const value_type* s, size_type pos,
1924 size_type n) const {
1925 if (pos < length()) {
1929 for (; i != finish; ++i) {
1930 if (traits_type::find(s, n, *i) == 0) {
1938 size_type find_first_not_of(const value_type* s,
1939 size_type pos = 0) const {
1940 return find_first_not_of(s, pos, traits_type::length(s));
1943 size_type find_first_not_of(value_type c, size_type pos = 0) const {
1944 return find_first_not_of(&c, pos, 1);
1947 size_type find_last_not_of(const basic_fbstring& str,
1948 size_type pos = npos) const {
1949 return find_last_not_of(str.data(), pos, str.length());
1952 size_type find_last_not_of(const value_type* s, size_type pos,
1953 size_type n) const {
1954 if (!this->empty()) {
1955 pos = std::min(pos, size() - 1);
1956 const_iterator i(begin() + pos);
1958 if (traits_type::find(s, n, *i) == 0) {
1961 if (i == begin()) break;
1967 size_type find_last_not_of(const value_type* s,
1968 size_type pos = npos) const {
1969 return find_last_not_of(s, pos, traits_type::length(s));
1972 size_type find_last_not_of (value_type c, size_type pos = npos) const {
1973 return find_last_not_of(&c, pos, 1);
1976 basic_fbstring substr(size_type pos = 0, size_type n = npos) const& {
1977 enforce(pos <= size(), std::__throw_out_of_range, "");
1978 return basic_fbstring(data() + pos, std::min(n, size() - pos));
1981 basic_fbstring substr(size_type pos = 0, size_type n = npos) && {
1982 enforce(pos <= size(), std::__throw_out_of_range, "");
1984 if (n < size()) resize(n);
1985 return std::move(*this);
1988 int compare(const basic_fbstring& str) const {
1989 // FIX due to Goncalo N M de Carvalho July 18, 2005
1990 return compare(0, size(), str);
1993 int compare(size_type pos1, size_type n1,
1994 const basic_fbstring& str) const {
1995 return compare(pos1, n1, str.data(), str.size());
1998 int compare(size_type pos1, size_type n1,
1999 const value_type* s) const {
2000 return compare(pos1, n1, s, traits_type::length(s));
2003 int compare(size_type pos1, size_type n1,
2004 const value_type* s, size_type n2) const {
2005 enforce(pos1 <= size(), std::__throw_out_of_range, "");
2006 procrustes(n1, size() - pos1);
2007 // The line below fixed by Jean-Francois Bastien, 04-23-2007. Thanks!
2008 const int r = traits_type::compare(pos1 + data(), s, std::min(n1, n2));
2009 return r != 0 ? r : n1 > n2 ? 1 : n1 < n2 ? -1 : 0;
2012 int compare(size_type pos1, size_type n1,
2013 const basic_fbstring& str,
2014 size_type pos2, size_type n2) const {
2015 enforce(pos2 <= str.size(), std::__throw_out_of_range, "");
2016 return compare(pos1, n1, str.data() + pos2,
2017 std::min(n2, str.size() - pos2));
2020 // Code from Jean-Francois Bastien (03/26/2007)
2021 int compare(const value_type* s) const {
2022 // Could forward to compare(0, size(), s, traits_type::length(s))
2023 // but that does two extra checks
2024 const size_type n1(size()), n2(traits_type::length(s));
2025 const int r = traits_type::compare(data(), s, std::min(n1, n2));
2026 return r != 0 ? r : n1 > n2 ? 1 : n1 < n2 ? -1 : 0;
2034 // non-member functions
2036 template <typename E, class T, class A, class S>
2038 basic_fbstring<E, T, A, S> operator+(const basic_fbstring<E, T, A, S>& lhs,
2039 const basic_fbstring<E, T, A, S>& rhs) {
2041 basic_fbstring<E, T, A, S> result;
2042 result.reserve(lhs.size() + rhs.size());
2043 result.append(lhs).append(rhs);
2044 return std::move(result);
2048 template <typename E, class T, class A, class S>
2050 basic_fbstring<E, T, A, S> operator+(basic_fbstring<E, T, A, S>&& lhs,
2051 const basic_fbstring<E, T, A, S>& rhs) {
2052 return std::move(lhs.append(rhs));
2056 template <typename E, class T, class A, class S>
2058 basic_fbstring<E, T, A, S> operator+(const basic_fbstring<E, T, A, S>& lhs,
2059 basic_fbstring<E, T, A, S>&& rhs) {
2060 if (rhs.capacity() >= lhs.size() + rhs.size()) {
2061 // Good, at least we don't need to reallocate
2062 return std::move(rhs.insert(0, lhs));
2064 // Meh, no go. Forward to operator+(const&, const&).
2065 auto const& rhsC = rhs;
2070 template <typename E, class T, class A, class S>
2072 basic_fbstring<E, T, A, S> operator+(basic_fbstring<E, T, A, S>&& lhs,
2073 basic_fbstring<E, T, A, S>&& rhs) {
2074 return std::move(lhs.append(rhs));
2078 template <typename E, class T, class A, class S>
2080 basic_fbstring<E, T, A, S> operator+(
2082 const basic_fbstring<E, T, A, S>& rhs) {
2084 basic_fbstring<E, T, A, S> result;
2085 const auto len = basic_fbstring<E, T, A, S>::traits_type::length(lhs);
2086 result.reserve(len + rhs.size());
2087 result.append(lhs, len).append(rhs);
2092 template <typename E, class T, class A, class S>
2094 basic_fbstring<E, T, A, S> operator+(
2096 basic_fbstring<E, T, A, S>&& rhs) {
2098 const auto len = basic_fbstring<E, T, A, S>::traits_type::length(lhs);
2099 if (rhs.capacity() >= len + rhs.size()) {
2100 // Good, at least we don't need to reallocate
2101 return std::move(rhs.insert(rhs.begin(), lhs, lhs + len));
2103 // Meh, no go. Do it by hand since we have len already.
2104 basic_fbstring<E, T, A, S> result;
2105 result.reserve(len + rhs.size());
2106 result.append(lhs, len).append(rhs);
2111 template <typename E, class T, class A, class S>
2113 basic_fbstring<E, T, A, S> operator+(
2115 const basic_fbstring<E, T, A, S>& rhs) {
2117 basic_fbstring<E, T, A, S> result;
2118 result.reserve(1 + rhs.size());
2119 result.push_back(lhs);
2125 template <typename E, class T, class A, class S>
2127 basic_fbstring<E, T, A, S> operator+(
2129 basic_fbstring<E, T, A, S>&& rhs) {
2131 if (rhs.capacity() > rhs.size()) {
2132 // Good, at least we don't need to reallocate
2133 return std::move(rhs.insert(rhs.begin(), lhs));
2135 // Meh, no go. Forward to operator+(E, const&).
2136 auto const& rhsC = rhs;
2141 template <typename E, class T, class A, class S>
2143 basic_fbstring<E, T, A, S> operator+(
2144 const basic_fbstring<E, T, A, S>& lhs,
2147 typedef typename basic_fbstring<E, T, A, S>::size_type size_type;
2148 typedef typename basic_fbstring<E, T, A, S>::traits_type traits_type;
2150 basic_fbstring<E, T, A, S> result;
2151 const size_type len = traits_type::length(rhs);
2152 result.reserve(lhs.size() + len);
2153 result.append(lhs).append(rhs, len);
2157 // C++11 21.4.8.1/10
2158 template <typename E, class T, class A, class S>
2160 basic_fbstring<E, T, A, S> operator+(
2161 basic_fbstring<E, T, A, S>&& lhs,
2164 return std::move(lhs += rhs);
2167 // C++11 21.4.8.1/11
2168 template <typename E, class T, class A, class S>
2170 basic_fbstring<E, T, A, S> operator+(
2171 const basic_fbstring<E, T, A, S>& lhs,
2174 basic_fbstring<E, T, A, S> result;
2175 result.reserve(lhs.size() + 1);
2177 result.push_back(rhs);
2181 // C++11 21.4.8.1/12
2182 template <typename E, class T, class A, class S>
2184 basic_fbstring<E, T, A, S> operator+(
2185 basic_fbstring<E, T, A, S>&& lhs,
2188 return std::move(lhs += rhs);
2191 template <typename E, class T, class A, class S>
2193 bool operator==(const basic_fbstring<E, T, A, S>& lhs,
2194 const basic_fbstring<E, T, A, S>& rhs) {
2195 return lhs.size() == rhs.size() && lhs.compare(rhs) == 0; }
2197 template <typename E, class T, class A, class S>
2199 bool operator==(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2200 const basic_fbstring<E, T, A, S>& rhs) {
2201 return rhs == lhs; }
2203 template <typename E, class T, class A, class S>
2205 bool operator==(const basic_fbstring<E, T, A, S>& lhs,
2206 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2207 return lhs.compare(rhs) == 0; }
2209 template <typename E, class T, class A, class S>
2211 bool operator!=(const basic_fbstring<E, T, A, S>& lhs,
2212 const basic_fbstring<E, T, A, S>& rhs) {
2213 return !(lhs == rhs); }
2215 template <typename E, class T, class A, class S>
2217 bool operator!=(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2218 const basic_fbstring<E, T, A, S>& rhs) {
2219 return !(lhs == rhs); }
2221 template <typename E, class T, class A, class S>
2223 bool operator!=(const basic_fbstring<E, T, A, S>& lhs,
2224 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2225 return !(lhs == rhs); }
2227 template <typename E, class T, class A, class S>
2229 bool operator<(const basic_fbstring<E, T, A, S>& lhs,
2230 const basic_fbstring<E, T, A, S>& rhs) {
2231 return lhs.compare(rhs) < 0; }
2233 template <typename E, class T, class A, class S>
2235 bool operator<(const basic_fbstring<E, T, A, S>& lhs,
2236 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2237 return lhs.compare(rhs) < 0; }
2239 template <typename E, class T, class A, class S>
2241 bool operator<(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2242 const basic_fbstring<E, T, A, S>& rhs) {
2243 return rhs.compare(lhs) > 0; }
2245 template <typename E, class T, class A, class S>
2247 bool operator>(const basic_fbstring<E, T, A, S>& lhs,
2248 const basic_fbstring<E, T, A, S>& rhs) {
2251 template <typename E, class T, class A, class S>
2253 bool operator>(const basic_fbstring<E, T, A, S>& lhs,
2254 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2257 template <typename E, class T, class A, class S>
2259 bool operator>(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2260 const basic_fbstring<E, T, A, S>& rhs) {
2263 template <typename E, class T, class A, class S>
2265 bool operator<=(const basic_fbstring<E, T, A, S>& lhs,
2266 const basic_fbstring<E, T, A, S>& rhs) {
2267 return !(rhs < lhs); }
2269 template <typename E, class T, class A, class S>
2271 bool operator<=(const basic_fbstring<E, T, A, S>& lhs,
2272 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2273 return !(rhs < lhs); }
2275 template <typename E, class T, class A, class S>
2277 bool operator<=(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2278 const basic_fbstring<E, T, A, S>& rhs) {
2279 return !(rhs < lhs); }
2281 template <typename E, class T, class A, class S>
2283 bool operator>=(const basic_fbstring<E, T, A, S>& lhs,
2284 const basic_fbstring<E, T, A, S>& rhs) {
2285 return !(lhs < rhs); }
2287 template <typename E, class T, class A, class S>
2289 bool operator>=(const basic_fbstring<E, T, A, S>& lhs,
2290 const typename basic_fbstring<E, T, A, S>::value_type* rhs) {
2291 return !(lhs < rhs); }
2293 template <typename E, class T, class A, class S>
2295 bool operator>=(const typename basic_fbstring<E, T, A, S>::value_type* lhs,
2296 const basic_fbstring<E, T, A, S>& rhs) {
2297 return !(lhs < rhs);
2301 template <typename E, class T, class A, class S>
2302 void swap(basic_fbstring<E, T, A, S>& lhs, basic_fbstring<E, T, A, S>& rhs) {
2306 // TODO: make this faster.
2307 template <typename E, class T, class A, class S>
2310 typename basic_fbstring<E, T, A, S>::value_type,
2311 typename basic_fbstring<E, T, A, S>::traits_type>&
2313 std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2314 typename basic_fbstring<E, T, A, S>::traits_type>& is,
2315 basic_fbstring<E, T, A, S>& str) {
2316 typename std::basic_istream<E, T>::sentry sentry(is);
2317 typedef std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2318 typename basic_fbstring<E, T, A, S>::traits_type>
2320 typedef typename __istream_type::ios_base __ios_base;
2321 size_t extracted = 0;
2322 auto err = __ios_base::goodbit;
2324 auto n = is.width();
2329 for (auto got = is.rdbuf()->sgetc(); extracted != size_t(n); ++extracted) {
2330 if (got == T::eof()) {
2331 err |= __ios_base::eofbit;
2335 if (isspace(got)) break;
2337 got = is.rdbuf()->snextc();
2341 err |= __ios_base::failbit;
2349 template <typename E, class T, class A, class S>
2351 std::basic_ostream<typename basic_fbstring<E, T, A, S>::value_type,
2352 typename basic_fbstring<E, T, A, S>::traits_type>&
2354 std::basic_ostream<typename basic_fbstring<E, T, A, S>::value_type,
2355 typename basic_fbstring<E, T, A, S>::traits_type>& os,
2356 const basic_fbstring<E, T, A, S>& str) {
2358 typename std::basic_ostream<
2359 typename basic_fbstring<E, T, A, S>::value_type,
2360 typename basic_fbstring<E, T, A, S>::traits_type>::sentry __s(os);
2362 typedef std::ostreambuf_iterator<
2363 typename basic_fbstring<E, T, A, S>::value_type,
2364 typename basic_fbstring<E, T, A, S>::traits_type> _Ip;
2365 size_t __len = str.size();
2367 (os.flags() & std::ios_base::adjustfield) == std::ios_base::left;
2368 if (__pad_and_output(_Ip(os),
2370 __left ? str.data() + __len : str.data(),
2373 os.fill()).failed()) {
2374 os.setstate(std::ios_base::badbit | std::ios_base::failbit);
2377 #elif defined(_MSC_VER)
2378 // MSVC doesn't define __ostream_insert
2379 os.write(str.data(), str.size());
2381 std::__ostream_insert(os, str.data(), str.size());
2386 #ifndef _LIBSTDCXX_FBSTRING
2388 template <typename E, class T, class A, class S>
2390 std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2391 typename basic_fbstring<E, T, A, S>::traits_type>&
2393 std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2394 typename basic_fbstring<E, T, A, S>::traits_type>& is,
2395 basic_fbstring<E, T, A, S>& str,
2396 typename basic_fbstring<E, T, A, S>::value_type delim) {
2397 // Use the nonstandard getdelim()
2398 char * buf = nullptr;
2401 // This looks quadratic but it really depends on realloc
2402 auto const newSize = size + 128;
2403 buf = static_cast<char*>(checkedRealloc(buf, newSize));
2404 is.getline(buf + size, newSize - size, delim);
2405 if (is.bad() || is.eof() || !is.fail()) {
2406 // done by either failure, end of file, or normal read
2407 size += std::strlen(buf + size);
2410 // Here we have failed due to too short a buffer
2411 // Minus one to discount the terminating '\0'
2413 assert(buf[size] == 0);
2414 // Clear the error so we can continue reading
2417 basic_fbstring<E, T, A, S> result(buf, size, size + 1,
2418 AcquireMallocatedString());
2423 template <typename E, class T, class A, class S>
2425 std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2426 typename basic_fbstring<E, T, A, S>::traits_type>&
2428 std::basic_istream<typename basic_fbstring<E, T, A, S>::value_type,
2429 typename basic_fbstring<E, T, A, S>::traits_type>& is,
2430 basic_fbstring<E, T, A, S>& str) {
2431 // Just forward to the version with a delimiter
2432 return getline(is, str, '\n');
2437 template <typename E1, class T, class A, class S>
2438 const typename basic_fbstring<E1, T, A, S>::size_type
2439 basic_fbstring<E1, T, A, S>::npos =
2440 static_cast<typename basic_fbstring<E1, T, A, S>::size_type>(-1);
2442 #ifndef _LIBSTDCXX_FBSTRING
2443 // basic_string compatibility routines
2445 template <typename E, class T, class A, class S>
2447 bool operator==(const basic_fbstring<E, T, A, S>& lhs,
2448 const std::string& rhs) {
2449 return lhs.compare(0, lhs.size(), rhs.data(), rhs.size()) == 0;
2452 template <typename E, class T, class A, class S>
2454 bool operator==(const std::string& lhs,
2455 const basic_fbstring<E, T, A, S>& rhs) {
2459 template <typename E, class T, class A, class S>
2461 bool operator!=(const basic_fbstring<E, T, A, S>& lhs,
2462 const std::string& rhs) {
2463 return !(lhs == rhs);
2466 template <typename E, class T, class A, class S>
2468 bool operator!=(const std::string& lhs,
2469 const basic_fbstring<E, T, A, S>& rhs) {
2470 return !(lhs == rhs);
2473 #if !defined(_LIBSTDCXX_FBSTRING)
2474 typedef basic_fbstring<char> fbstring;
2477 // fbstring is relocatable
2478 template <class T, class R, class A, class S>
2479 FOLLY_ASSUME_RELOCATABLE(basic_fbstring<T, R, A, S>);
2482 _GLIBCXX_END_NAMESPACE_VERSION
2485 } // namespace folly
2487 #ifndef _LIBSTDCXX_FBSTRING
2489 // Hash functions to make fbstring usable with e.g. hash_map
2491 // Handle interaction with different C++ standard libraries, which
2492 // expect these types to be in different namespaces.
2494 #define FOLLY_FBSTRING_HASH1(T) \
2496 struct hash< ::folly::basic_fbstring<T> > { \
2497 size_t operator()(const ::folly::fbstring& s) const { \
2498 return ::folly::hash::fnv32_buf(s.data(), s.size()); \
2502 // The C++11 standard says that these four are defined
2503 #define FOLLY_FBSTRING_HASH \
2504 FOLLY_FBSTRING_HASH1(char) \
2505 FOLLY_FBSTRING_HASH1(char16_t) \
2506 FOLLY_FBSTRING_HASH1(char32_t) \
2507 FOLLY_FBSTRING_HASH1(wchar_t)
2515 #if FOLLY_HAVE_DEPRECATED_ASSOC
2516 #if defined(_GLIBCXX_SYMVER) && !defined(__BIONIC__)
2517 namespace __gnu_cxx {
2521 } // namespace __gnu_cxx
2522 #endif // _GLIBCXX_SYMVER && !__BIONIC__
2523 #endif // FOLLY_HAVE_DEPRECATED_ASSOC
2525 #undef FOLLY_FBSTRING_HASH
2526 #undef FOLLY_FBSTRING_HASH1
2528 #endif // _LIBSTDCXX_FBSTRING
2530 #pragma GCC diagnostic pop
2532 #undef FBSTRING_DISABLE_ADDRESS_SANITIZER
2534 #undef FBSTRING_LIKELY
2535 #undef FBSTRING_UNLIKELY
2537 #endif // FOLLY_BASE_FBSTRING_H_