C17中是否使用“std :: is_invocable”替换“std :: is_callable”？

cppref已经删除std :: is_callable的入口页面,并改用std :: is_invocable条目页面.

但是,std :: is_callable在Visual Studio 2017中仍然可用.

在C 17中使用std :: is_invocable正式表示std :: is_callable [replace | deprecated | removed]

解决方法

是的,is_callable已经被重命名为is_invocable,如 p0604r0所述.本文包括这个决定的理由：

Rename is_callable to is_invocable: is_callable would be the most natural name for a trait that answers the question whether a function call expression would be valid or not,which is a strict subset of the expressions,INVOKE supports,furthermore the changed name is_invocable much clearer expresses its meaning. Releasing the name is_callable allows us in the future to possibly introduce a pure is_callable trait.