Const vs. constexpr vs. consteval vs. constinit in C++20

Re:Const vs. constexpr vs. consteval vs. constinit in C++20 by kllrnohj on Monday November 28, 2022 @07:40PM (#33782090)

std::mem_fn will effectively give you the underlying function that takes a pointer. Strictly speaking mem_fn is defined to generate the wrapper function, but in practice the optimizer is just going to strip that away and call the name-mangled function directly.

Example: https://godbolt.org/z/6Y1raxMce

[ Parent | on HN ]

Re:Const vs. constexpr vs. consteval vs. constinit in C++20 by Matheus28 on Tuesday November 29, 2022 @03:10AM (#33784898)

You can just use member function pointers without the wrapper. The syntax for calling them is a bit uglier though.

[ Parent | on HN ]

Re:Const vs. constexpr vs. consteval vs. constinit in C++20 by kllrnohj on Thursday December 01, 2022 @04:49PM (#33823370)

Yup, but then the call syntax is different so it fails to achieve the "Universal Function Call Syntax" that OP was asking for which std::mem_fn provides.

[ Parent | on HN ]

Re:Const vs. constexpr vs. consteval vs. constinit in C++20 by gavinray on Tuesday November 29, 2022 @03:45PM (#33793045)

Whoa, this is really cool, thanks for posting

[ Parent | on HN ]