Namespaces
Variants
Views
Actions

std::source_location::line

From cppreference.com
 
 
Utilities library
Language support
Type support (basic types, RTTI)
Library feature-test macros (C++20)
Dynamic memory management
Program utilities
Coroutine support (C++20)
Variadic functions
Debugging support
(C++26)
Three-way comparison
(C++20)
(C++20)(C++20)(C++20)
(C++20)(C++20)(C++20)
General utilities
Date and time
Function objects
Formatting library (C++20)
(C++11)
Relational operators (deprecated in C++20)
Integer comparison functions
(C++20)(C++20)(C++20)   
(C++20)
Swap and type operations
(C++14)
(C++11)
(C++11)
(C++11)
(C++17)
Common vocabulary types
(C++11)
(C++17)
(C++17)
(C++17)
(C++11)
(C++17)
(C++23)
Elementary string conversions
(C++17)
(C++17)

 
 
constexpr std::uint_least32_t line() const noexcept;
(since C++20)

Returns the line number represented by this object.

Contents

[edit] Parameters

(none)

[edit] Return value

The line number represented by this object.

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

[edit] Example

#include <iostream>
#include <string_view>
#include <source_location>
 
inline void cur_line(
    const std::string_view message = "",
    const std::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) --

[edit] See also

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