diff options
Diffstat (limited to 'compat/macros.hpp')
| -rw-r--r-- | compat/macros.hpp | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/compat/macros.hpp b/compat/macros.hpp index 61c49975..0807df4c 100644 --- a/compat/macros.hpp +++ b/compat/macros.hpp @@ -44,8 +44,13 @@ // from now only C++ +#include <utility> + //#define once_only(...) do { static bool once__ = false; if (!once__) { once__ = true; __VA_ARGS__; } } while(false) -#define once_only(expr) ([&] { static decltype(auto) ret___1132 = (expr); return ret___1132; }()) +//#define once_only(expr) ([&] { static decltype(auto) ret___1132 = (expr); return (decltype(ret___1132) const&) ret___1132; }()) + +#define eval_once__2(expr, ident) (([&] { static bool ident = ((expr), true); (void)(ident); })) +#define eval_once(expr) eval_once__2(expr, PP_CAT(eval_once_init__, __COUNTER__)) #include <type_traits> |