diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/o3tl/string_view.hxx | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/include/o3tl/string_view.hxx b/include/o3tl/string_view.hxx index 5ebbb0b9f044..b66ba1175a57 100644 --- a/include/o3tl/string_view.hxx +++ b/include/o3tl/string_view.hxx @@ -13,6 +13,7 @@ #include <cassert> #include <cstddef> +#include <string> #include <string_view> #include <rtl/ustring.h> @@ -46,6 +47,66 @@ inline std::string_view getToken(std::string_view sv, char delimiter, std::size_ } return t; } + +// Implementations of C++20 std::basic_string_view::starts_with and +// std::basic_string_view::ends_with, until we can use those directly on all platforms: +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool starts_with(std::basic_string_view<charT, traits> sv, + std::basic_string_view<charT, traits> x) noexcept +{ +#if defined __cpp_lib_starts_ends_with + return sv.starts_with(x); +#else + return sv.substr(0, x.size()) == x; +#endif +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool starts_with(std::basic_string_view<charT, traits> sv, charT x) noexcept +{ +#if defined __cpp_lib_starts_ends_with + return sv.starts_with(x); +#else + return !sv.empty() && traits::eq(sv.front(), x); +#endif +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool starts_with(std::basic_string_view<charT, traits> sv, charT const* x) +{ +#if defined __cpp_lib_starts_ends_with + return sv.starts_with(x); +#else + return starts_with(sv, std::basic_string_view<charT, traits>(x)); +#endif +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool ends_with(std::basic_string_view<charT, traits> sv, + std::basic_string_view<charT, traits> x) noexcept +{ +#if defined __cpp_lib_ends_ends_with + return sv.ends_with(x); +#else + return sv.size() >= x.size() + && sv.compare(sv.size() - x.size(), std::basic_string_view<charT, traits>::npos, x) == 0; +#endif +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool ends_with(std::basic_string_view<charT, traits> sv, charT x) noexcept +{ +#if defined __cpp_lib_ends_ends_with + return sv.ends_with(x); +#else + return !sv.empty() && traits::eq(sv.back(), x); +#endif +} +template <typename charT, typename traits = std::char_traits<charT>> +constexpr bool ends_with(std::basic_string_view<charT, traits> sv, charT const* x) +{ +#if defined __cpp_lib_ends_ends_with + return sv.ends_with(x); +#else + return ends_with(sv, std::basic_string_view<charT, traits>(x)); +#endif +} } /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */ |