std::basic_string<CharT,Traits,Allocator>::insert_range - cppreference.com

From cppreference.com

template< container-compatible-range<CharT> R > constexpr iterator insert_range( const_iterator pos, R&& rg );		(since C++23)

Inserts characters from the range rg before the element (if any) pointed by pos.

Equivalent to

return insert(pos - begin(),
    std::basic_string(
        std::from_range,
        std::forward<R>(rg),
        get_allocator())
);

If pos is not a valid iterator on *this, the behavior is undefined.

Parameters

Return value

An iterator which refers to the first inserted character, or pos if no characters were inserted because rg was empty.

Complexity

Linear in size of rg.

Exceptions

If std::allocator_traits<Allocator>::allocate throws an exception, it is rethrown.

If the operation would cause size() to exceed max_size(), throws std::length_error.

If an exception is thrown for any reason, this function has no effect (strong exception safety guarantee).

Notes

Feature-test macro	Value	Std	Feature
`__cpp_lib_containers_ranges`	`202202L`	(C++23)	member functions that accept container compatible range

Example

#include <cassert>
#include <iterator>
#include <string>

int main()
{
    const auto source = {'l', 'i', 'b', '_'};
    std::string target{"__cpp_containers_ranges"};
    //                        ^insertion will occur
    //                         before this position

    const auto pos = target.find("container");
    assert(pos != target.npos);
    auto iter = std::next(target.begin(), pos);

#ifdef __cpp_lib_containers_ranges
    target.insert_range(iter, source);
#else
    target.insert(iter, source.begin(), source.end());
#endif

    assert(target == "__cpp_lib_containers_ranges");
    //                      ^^^^
}