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std::basic_stacktrace<Allocator>::rbegin, std::basic_stacktrace<Allocator>::crbegin

const_reverse_iterator rbegin()  const noexcept;
 (1) (since C++23) 
const_reverse_iterator crbegin() const noexcept;
 (2) (since C++23)

Returns a reverse iterator to the first entry of the reversed basic_stacktrace. It corresponds to the last entry of the original basic_stacktrace. If the basic_stacktrace is empty, the returned iterator is equal to rend().

range-rbegin-rend.svg

Parameters

(none).

Return value

Reverse iterator to the first entry.

Complexity

Constant.

Example

#include <algorithm>
#include <iostream>
#include <stacktrace>
 
int main()
{
    auto trace       = std::stacktrace::current();
    auto empty_trace = std::stacktrace{};
 
    // Print stacktrace.
    std::for_each(trace.rbegin(), trace.rend(),
                  [](const auto& f) { std::cout << f << '\n'; });
 
    if (empty_trace.rbegin() == empty_trace.rend())
        std::cout << "stacktrace 'empty_trace' is indeed empty.\n";
}

Possible output:

0x0000000000402A29 in ./prog.exe
__libc_start_main in /lib/x86_64-linux-gnu/libc.so.6
0x0000000000402BA5 in ./prog.exe
stacktrace 'empty_trace' is indeed empty.

See also

(C++23)
 returns a reverse iterator to the end
(public member function)

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