std::source_location::line

 

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std::source_location

Member functions

Creation

source_location::source_location

source_location::current

Field access

source_location::line

source_location::column

source_location::file_name

source_location::function_name

 

constexprstd::uint_least32_t line()constnoexcept;		(since C++20)

Returns the line number represented by this object.

Parameters

(none)

Return value

The line number represented by this object.

An implementation is encouraged to return 0 when the line number is unknown.

Example

Run this code

#include <iostream>#include <string_view>#include <source_location>   inlinevoid cur_line(conststd::string_view message ="", conststd::source_location& location = std::source_location::current()){std::cout<< location.line()// <- the line # of a call site<<") "<< message;}   int main(){ cur_line("++\n"); cur_line();std::cout<<"Hello,\n"; cur_line();std::cout<<"C++20!\n"; cur_line("--\n");}

Output:

17) ++ 18) Hello, 19) C++20! 20) --

See also

column	return the column number represented by this object (public member function)
file_name	return the file name represented by this object (public member function)
function_name	return the name of the function represented by this object, if any (public member function)
source_line	gets the line number that lexically relates the evaluation represented by the stacktrace_entry (public member function of std::stacktrace_entry)
Filename and line information