In order to make pytorch headers consumable from cpp20 code bases, … (#79985)
… all instances of std::result_of and std:result_of_t are conditionally replaced by std::invoke_result and std::invoke_result_t if __cpp_lib_is_invocable >= 201703L. std::invoke_result was only introduced in c++17, so it should probably not be required yet.
Fixes #71657 and a small part of #69290
Tested on Centos 7 / gcc11 + a private project that requires cpp20.
I think the main questions to check by a maintainer are,
- whether my choices of preprocessor blocks are appropriate
- whether there are any very subtle differences between std::result_of and std::invoke_result that I have missed
- whether in any of the replacements the 'new' side can/should be simplified further
Pull Request resolved: https://github.com/pytorch/pytorch/pull/79985
Approved by: https://github.com/ezyang
