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std::source...rce_location(3)  C++ Standard Libary std::source...rce_location(3)

NAME
     std::source_location::source_location  - std::source_location::source_loca-
     tion

Synopsis
	constexpr source_location() noexcept;		     (1) (since C++20)
	source_location( const source_location& other );     (2) (since C++20)
	source_location( source_location&& other ) noexcept; (3) (since C++20)

	1) Constructs a source_location object of unspecified value.
	2,3) Copy and move constructors. It  is  unspecified  whether  they  are
     trivial and/or
	constexpr.

Parameters
	other - another source_location to copy or move from

Example
     // Run this code

      #include <iomanip>
      #include <iostream>
      #include <ranges>
      #include <source_location>
      #include <string_view>
      #include <vector>

      // GCC specific type name printer
      #if (__GNUG__ >= 11)
      template<typename T>
      auto  type_name_helper(const  std::source_location  s  = std::source_loca-
     tion::current())
      {
	  using std::operator""sv;
	  const std::string_view fun_name{s.function_name()};
	  constexpr auto prefix{"[with T = "sv};
	  const auto type_name_begin{fun_name.find(prefix)};
	  if (""sv.npos == type_name_begin)
	      return ""sv;
	  const std::size_t first{type_name_begin + prefix.length()};
	  return std::string_view{fun_name.cbegin() + first,  fun_name.cend()  -
     1};
      }

      template<typename T>
      auto type_name() { return type_name_helper<T>(); }
      #endif

      void print(std::string_view const comment, std::source_location const l)
      {
	  std::cout << comment << ":\n"
		    <<	"   file_name	   :  " << std::quoted(l.file_name()) <<
     '\n'
		    << "  function_name : " << std::quoted(l.function_name()) <<
     '\n'
		    << "  line		: " << l.line() << '\n'
		    << "  column	: " << l.column() << '\n';
      }

      int main()
      {
	  constexpr std::source_location default_constructed;
	  print("default constructed", default_constructed);

	  constexpr std::source_location  current  =  std::source_location::cur-
     rent();
	  print("current", current);

      #if (__GNUG__ >= 11)
	  const std::vector<std::vector<int>> v{{1,2}, {3,4,5}, {6}};
	  auto jv = std::ranges::join_view(v);
	  std::cout << '\n'
		    << '[' << type_name<int>() << "]\n"
		    << '[' << type_name<double*>() << "]\n"
		    << '[' << type_name<decltype([](){})>() << "]\n"
		    << '[' << type_name<decltype(type_name<int>())>() << "]\n"
		    << '[' << type_name<decltype(jv)>() << "]\n";
      #endif
      }

Possible output:
      default constructed:
	file_name     : ""
	function_name : ""
	line	      : 0
	column	      : 0
      current:
	file_name     : "main.cpp"
	function_name : "int main()"
	line	      : 39
	column	      : 75

      [int]
      [double*]
      [main()::<lambda()>]
      [std::basic_string_view<char>]
      [std::ranges::join_view<std::ranges::ref_view<const  std::vector<std::vec-
     tor<int> > > >]

See also
	current       constructs a new source_location corresponding to the  lo-
     cation of the
	[static]      call site
		      (public static member function)
	constructor   constructs a new stacktrace_entry
	(C++23)       (public member function of std::stacktrace_entry)

http://cppreference.com 	   2024.06.10	   std::source...rce_location(3)
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