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| author | Nick Krichevsky <njk828@gmail.com> | 2021-10-10 05:01:47 +0300 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-10-10 05:01:47 +0300 |
| commit | 4a02ad94f42841fc718bbcf128e0b674b336a074 (patch) | |
| tree | 7c7b73e16bf2ca3bf480670a437c44e5e445ca91 | |
| parent | c641241a87cba7efdcb8f2145649763940784982 (diff) | |
Include <optional> if possible to check if we can use the feature (#309)
Fixes #303
| -rw-r--r-- | include/cxxopts.hpp | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/include/cxxopts.hpp b/include/cxxopts.hpp index 58b5d45..870755a 100644 --- a/include/cxxopts.hpp +++ b/include/cxxopts.hpp @@ -51,9 +51,14 @@ THE SOFTWARE. # include <regex> #endif // CXXOPTS_NO_REGEX -#ifdef __cpp_lib_optional -#include <optional> -#define CXXOPTS_HAS_OPTIONAL +// Nonstandard before C++17, which is coincidentally what we also need for <optional> +#ifdef __has_include +# if __has_include(<optional>) +# include <optional> +# ifdef __cpp_lib_optional +# define CXXOPTS_HAS_OPTIONAL +# endif +# endif #endif #if __cplusplus >= 201603L @@ -1361,7 +1366,7 @@ namespace cxxopts { return m_count; } - + #if defined(CXXOPTS_NULL_DEREF_IGNORE) #pragma GCC diagnostic pop #endif |