Re: We have a new standard!

On 02/01/2025 16:35, Michael S wrote:

On Thu, 2 Jan 2025 13:51:53 +0100
David Brown <david.brown@hesbynett.no> wrote:
 

>
Could this all have been done from the start of C++?  In theory, yes
- in practice no.  std::format and std::print rely on various modern
C++ features, such as compile-time evaluation of functions,

 It does not look like dependence of std::format on compile-time
evaluation is a requirement of standard rather than implementation
choice of g++ and of clang++.
 MSVC 19.30.30706 compiles the following code just fine:
 #include <cstdio>
#include <format>
 int main(int argc, char** argv)
{
   if (argc >= 3) {
     std::string s = std::format(argv[1], argv[2]);
     printf("%s\n", s.c_str());
   }
   return 0;
}
 When run, it produces expected results.
 Or, may be, it's because this version of MSVC is not fully C++20
complient.
 

<https://en.cppreference.com/w/cpp/utility/format/format>
Apparently P2216R3 made compile-time checks for std::format a requirement.  I don't know where that fits with standard versions, or compiler support.  I am just going by what it says in the reference here.