Added a better check for openssl

[folly.git] / folly / Range.h

diff --git a/folly/Range.h b/folly/Range.h
index 4913aef403580330a3609e474ff315791913273e..0b63f45770efa5f29ec579b48d23c86d37bdd962 100644 (file)
--- a/folly/Range.h
+++ b/folly/Range.h
@@ -17,8 +17,7 @@
 // @author Mark Rabkin (mrabkin@fb.com)
 // @author Andrei Alexandrescu (andrei.alexandrescu@fb.com)
 
-#ifndef FOLLY_RANGE_H_
-#define FOLLY_RANGE_H_
+#pragma once
 
 #include <folly/FBString.h>
 #include <folly/Portability.h>
@@ -354,8 +353,13 @@ public:
     reset(str.data(), str.size());
   }
 
-  size_type size() const {
-    assert(b_ <= e_);
+  constexpr size_type size() const {
+    // It would be nice to assert(b_ <= e_) here.  This can be achieved even
+    // in a C++11 compatible constexpr function:
+    // http://ericniebler.com/2014/09/27/assert-and-constexpr-in-cxx11/
+    // Unfortunately current gcc versions have a bug causing it to reject
+    // this check in a constexpr function:
+    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71448
     return e_ - b_;
   }
   size_type walk_size() const {
@@ -1081,6 +1085,10 @@ size_t rfind(const Range<T>& haystack,
 // specialization for StringPiece
 template <>
 inline size_t qfind(const Range<const char*>& haystack, const char& needle) {
+  // memchr expects a not-null pointer, early return if the range is empty.
+  if (haystack.empty()) {
+    return std::string::npos;
+  }
   auto pos = static_cast<const char*>(
     ::memchr(haystack.data(), needle, haystack.size()));
   return pos == nullptr ? std::string::npos : pos - haystack.data();
@@ -1088,6 +1096,10 @@ inline size_t qfind(const Range<const char*>& haystack, const char& needle) {
 
 template <>
 inline size_t rfind(const Range<const char*>& haystack, const char& needle) {
+  // memchr expects a not-null pointer, early return if the range is empty.
+  if (haystack.empty()) {
+    return std::string::npos;
+  }
   auto pos = static_cast<const char*>(
     ::memrchr(haystack.data(), needle, haystack.size()));
   return pos == nullptr ? std::string::npos : pos - haystack.data();
@@ -1097,6 +1109,10 @@ inline size_t rfind(const Range<const char*>& haystack, const char& needle) {
 template <>
 inline size_t qfind(const Range<const unsigned char*>& haystack,
                     const unsigned char& needle) {
+  // memchr expects a not-null pointer, early return if the range is empty.
+  if (haystack.empty()) {
+    return std::string::npos;
+  }
   auto pos = static_cast<const unsigned char*>(
     ::memchr(haystack.data(), needle, haystack.size()));
   return pos == nullptr ? std::string::npos : pos - haystack.data();
@@ -1105,6 +1121,10 @@ inline size_t qfind(const Range<const unsigned char*>& haystack,
 template <>
 inline size_t rfind(const Range<const unsigned char*>& haystack,
                     const unsigned char& needle) {
+  // memchr expects a not-null pointer, early return if the range is empty.
+  if (haystack.empty()) {
+    return std::string::npos;
+  }
   auto pos = static_cast<const unsigned char*>(
     ::memrchr(haystack.data(), needle, haystack.size()));
   return pos == nullptr ? std::string::npos : pos - haystack.data();
@@ -1142,10 +1162,16 @@ struct hasher<folly::Range<T*>,
   }
 };
 
+/**
+ * Ubiquitous helper template for knowing what's a string
+ */
+template <class T> struct IsSomeString {
+  enum { value = std::is_same<T, std::string>::value
+         || std::is_same<T, fbstring>::value };
+};
+
 }  // !namespace folly
 
 #pragma GCC diagnostic pop
 
 FOLLY_ASSUME_FBVECTOR_COMPATIBLE_1(folly::Range);
-
-#endif // FOLLY_RANGE_H_