diff options
Diffstat (limited to 'libstdc++-v3/include')
| -rw-r--r-- | libstdc++-v3/include/experimental/string_view | 24 | ||||
| -rw-r--r-- | libstdc++-v3/include/experimental/string_view.tcc | 6 |
2 files changed, 23 insertions, 7 deletions
diff --git a/libstdc++-v3/include/experimental/string_view b/libstdc++-v3/include/experimental/string_view index 6a95e8d0bd0..000d317c5c5 100644 --- a/libstdc++-v3/include/experimental/string_view +++ b/libstdc++-v3/include/experimental/string_view @@ -43,7 +43,7 @@ #include <string> #include <limits> -namespace std //_GLIBCXX_VISIBILITY(default) +namespace std _GLIBCXX_VISIBILITY(default) { namespace experimental { @@ -66,6 +66,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION * _CharT* _M_str * size_t _M_len * @endcode + * + * A basic_string_view represents an empty string with a static constexpr + * length one string: + * + * @code + * static constexpr value_type _S_empty_str[1]{0}; + * @endcode */ template<typename _CharT, typename _Traits = char_traits<_CharT>> class basic_string_view @@ -92,7 +99,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION constexpr basic_string_view() noexcept - : _M_len{0}, _M_str{nullptr} + : _M_len{0}, _M_str{_S_empty_str} { } constexpr basic_string_view(const basic_string_view&) noexcept = default; @@ -104,11 +111,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { } constexpr basic_string_view(const _CharT* __str) - : _M_len{__str == nullptr ? 0 : traits_type::length(__str)}, _M_str{__str} + : _M_len{__str == nullptr ? 0 : traits_type::length(__str)}, + _M_str{__str == nullptr ? _S_empty_str : __str} { } constexpr basic_string_view(const _CharT* __str, size_type __len) - : _M_len{__len}, _M_str{__str} + : _M_len{__str == nullptr ? 0 :__len}, + _M_str{__str == nullptr || __len == 0 ? _S_empty_str : __str} { } basic_string_view& @@ -185,7 +194,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION "(which is %zu) >= this->size() " "(which is %zu)"), __pos, this->size()), - *static_cast<pointer>(nullptr)); + _S_empty_str[0]); } constexpr const _CharT& @@ -211,7 +220,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION clear() noexcept { this->_M_len = 0; - this->_M_str = nullptr; + this->_M_str = _S_empty_str; } void @@ -408,6 +417,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } private: + static constexpr const int _S_compare(size_type __n1, size_type __n2) noexcept { @@ -418,6 +428,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION : static_cast<int>(difference_type{__n1 - __n2}); } + static constexpr value_type _S_empty_str[1]{}; + size_t _M_len; const _CharT* _M_str; }; diff --git a/libstdc++-v3/include/experimental/string_view.tcc b/libstdc++-v3/include/experimental/string_view.tcc index af334b456ca..eeccb026344 100644 --- a/libstdc++-v3/include/experimental/string_view.tcc +++ b/libstdc++-v3/include/experimental/string_view.tcc @@ -40,13 +40,17 @@ # include <bits/c++14_warning.h> #else -namespace std //_GLIBCXX_VISIBILITY(default) +namespace std _GLIBCXX_VISIBILITY(default) { namespace experimental { _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _CharT, typename _Traits> + constexpr _CharT + basic_string_view<_CharT, _Traits>::_S_empty_str[1]; + + template<typename _CharT, typename _Traits> typename basic_string_view<_CharT, _Traits>::size_type basic_string_view<_CharT, _Traits>:: find(const _CharT* __str, size_type __pos, size_type __n) const noexcept |