Function operator[]

include/boost/stacktrace/stacktrace.hpp:259–261

@param frame_no Zero based index of frame to return. 0 is the function index where stacktrace was constructed and index close to this->size() contains function `main()`. @returns frame that references the actual frame info, stored inside *this. @b Complexity: O(1). @b Async-Handler-Safety: \asyncsafe.

    ///
    /// @b Async-Handler-Safety: \asyncsafe.
    const_reference operator[](std::size_t frame_no) const noexcept {
        return impl_[frame_no];
    }

    /// @b Complexity: O(1)
    ///