logging: fix compiler compatibility for one more constexpr function

[folly.git] / folly / Conv.h

diff --git a/folly/Conv.h b/folly/Conv.h
index 6f98b4fabc69e71e746c2c29b7179bc7feda60ed..72518d808f5ad895ad04c33eadb5a87a711f5cc9 100644 (file)
--- a/folly/Conv.h
+++ b/folly/Conv.h
@@ -558,7 +558,8 @@ toAppend(Src value, Tgt * result) {
   if (value < 0) {
     result->push_back('-');
     result->append(
-        buffer, uint64ToBufferUnsafe(uint64_t(-uint64_t(value)), buffer));
+        buffer,
+        uint64ToBufferUnsafe(~static_cast<uint64_t>(value) + 1, buffer));
   } else {
     result->append(buffer, uint64ToBufferUnsafe(uint64_t(value), buffer));
   }
@@ -985,11 +986,12 @@ to(Src value) {
  * toDelim<SomeString>(SomeString str) returns itself.
  */
 template <class Tgt, class Delim, class Src>
-typename std::enable_if<IsSomeString<Tgt>::value &&
-                            std::is_same<Tgt, Src>::value,
-                        Tgt>::type
-toDelim(const Delim& /* delim */, const Src& value) {
-  return value;
+typename std::enable_if<
+    IsSomeString<Tgt>::value &&
+        std::is_same<Tgt, typename std::decay<Src>::type>::value,
+    Tgt>::type
+toDelim(const Delim& /* delim */, Src&& value) {
+  return std::forward<Src>(value);
 }
 
 /**
@@ -1164,7 +1166,7 @@ to(const char* b, const char* e) {
  * Parsing strings to numeric types.
  */
 template <typename Tgt>
-FOLLY_WARN_UNUSED_RESULT inline typename std::enable_if<
+FOLLY_NODISCARD inline typename std::enable_if<
     std::is_arithmetic<Tgt>::value,
     Expected<StringPiece, ConversionCode>>::type
 parseTo(StringPiece src, Tgt& out) {
@@ -1179,13 +1181,14 @@ parseTo(StringPiece src, Tgt& out) {
 namespace detail {
 
 /**
- * Bool to integral doesn't need any special checks, and this
+ * Bool to integral/float doesn't need any special checks, and this
  * overload means we aren't trying to see if a bool is less than
  * an integer.
  */
 template <class Tgt>
 typename std::enable_if<
-    !std::is_same<Tgt, bool>::value && std::is_integral<Tgt>::value,
+    !std::is_same<Tgt, bool>::value &&
+        (std::is_integral<Tgt>::value || std::is_floating_point<Tgt>::value),
     Expected<Tgt, ConversionCode>>::type
 convertTo(const bool& value) noexcept {
   return static_cast<Tgt>(value ? 1 : 0);
@@ -1204,7 +1207,8 @@ typename std::enable_if<
     Expected<Tgt, ConversionCode>>::type
 convertTo(const Src& value) noexcept {
   /* static */ if (
-      std::numeric_limits<Tgt>::max() < std::numeric_limits<Src>::max()) {
+      folly::_t<std::make_unsigned<Tgt>>(std::numeric_limits<Tgt>::max()) <
+      folly::_t<std::make_unsigned<Src>>(std::numeric_limits<Src>::max())) {
     if (greater_than<Tgt, std::numeric_limits<Tgt>::max()>(value)) {
       return makeUnexpected(ConversionCode::ARITH_POSITIVE_OVERFLOW);
     }
@@ -1239,7 +1243,7 @@ convertTo(const Src& value) noexcept {
       return makeUnexpected(ConversionCode::ARITH_NEGATIVE_OVERFLOW);
     }
   }
-  return boost::implicit_cast<Tgt>(value);
+  return static_cast<Tgt>(value);
 }
 
 /**
@@ -1369,7 +1373,7 @@ typename std::enable_if<detail::IsArithToArith<Tgt, Src>::value, Tgt>::type to(
  * }
  ******************************************************************************/
 template <class T>
-FOLLY_WARN_UNUSED_RESULT typename std::enable_if<
+FOLLY_NODISCARD typename std::enable_if<
     std::is_enum<T>::value,
     Expected<StringPiece, ConversionCode>>::type
 parseTo(StringPiece in, T& out) noexcept {
@@ -1379,7 +1383,7 @@ parseTo(StringPiece in, T& out) noexcept {
   return restOrError;
 }
 
-FOLLY_WARN_UNUSED_RESULT
+FOLLY_NODISCARD
 inline Expected<StringPiece, ConversionCode> parseTo(
     StringPiece in,
     StringPiece& out) noexcept {
@@ -1387,7 +1391,7 @@ inline Expected<StringPiece, ConversionCode> parseTo(
   return StringPiece{in.end(), in.end()};
 }
 
-FOLLY_WARN_UNUSED_RESULT
+FOLLY_NODISCARD
 inline Expected<StringPiece, ConversionCode> parseTo(
     StringPiece in,
     std::string& out) {
@@ -1396,7 +1400,7 @@ inline Expected<StringPiece, ConversionCode> parseTo(
   return StringPiece{in.end(), in.end()};
 }
 
-FOLLY_WARN_UNUSED_RESULT
+FOLLY_NODISCARD
 inline Expected<StringPiece, ConversionCode> parseTo(
     StringPiece in,
     fbstring& out) {
@@ -1533,7 +1537,7 @@ tryTo(const Src& value) {
 template <class Tgt, class Src>
 typename std::enable_if<
     std::is_enum<Tgt>::value && !std::is_same<Src, Tgt>::value,
-    Tgt>::type
+    Expected<Tgt, ConversionCode>>::type
 tryTo(const Src& value) {
   using I = typename std::underlying_type<Tgt>::type;
   return tryTo<I>(value).then([](I i) { return static_cast<Tgt>(i); });