diff options
Diffstat (limited to 'absl/strings/str_cat.h')
| -rw-r--r-- | absl/strings/str_cat.h | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/absl/strings/str_cat.h b/absl/strings/str_cat.h index fcd48c4e..d5f71ff0 100644 --- a/absl/strings/str_cat.h +++ b/absl/strings/str_cat.h @@ -374,14 +374,24 @@ class AlphaNum { const char* data() const { return piece_.data(); } absl::string_view Piece() const { return piece_; } - // Normal enums are already handled by the integer formatters. - // This overload matches only scoped enums. + // Match unscoped enums. Use integral promotion so that a `char`-backed + // enum becomes a wider integral type AlphaNum will accept. template <typename T, typename = typename std::enable_if< - std::is_enum<T>{} && !std::is_convertible<T, int>{} && + std::is_enum<T>{} && std::is_convertible<T, int>{} && !strings_internal::HasAbslStringify<T>::value>::type> AlphaNum(T e) // NOLINT(runtime/explicit) - : AlphaNum(static_cast<typename std::underlying_type<T>::type>(e)) {} + : AlphaNum(+e) {} + + // This overload matches scoped enums. We must explicitly cast to the + // underlying type, but use integral promotion for the same reason as above. + template <typename T, + typename std::enable_if< + std::is_enum<T>{} && !std::is_convertible<T, int>{} && + !strings_internal::HasAbslStringify<T>::value, + char*>::type = nullptr> + AlphaNum(T e) // NOLINT(runtime/explicit) + : AlphaNum(+static_cast<typename std::underlying_type<T>::type>(e)) {} // vector<bool>::reference and const_reference require special help to // convert to `AlphaNum` because it requires two user defined conversions. |