Create a string that has the same value as the substring of the optionally specified numChars length starting at the beginning of the specified characterString. If numChars is not specified, CHAR_TRAITS::length(characterString) is used. Optionally specify the basicAllocator used to supply memory. If basicAllocator is not specified, a default-constructed allocator is used. Throw out_of_range if numChars >= npos.
Declared in <bslstl_string.h>
basic_string(
char32_t const* characterString,
size_type numChars,
allocator<char32_t> const& basicAllocator = ALLOCATOR());