Deduce the template parameters CHAR_TYPE, TRAITS, and ALLOCATOR from the corresponding template parameters of the bsl::basic_string passed to the constructor of basic_string. This deduction guide does not participate unless the specified ALLOC is convertible to ALLOCATOR.
Declared in <bslstl_string.h>
template<
class CHAR_TYPE,
class CHAR_TRAITS,
class ALLOCATOR,
class ALLOC,
class SZ = allocator_traits<ALLOCATOR>::size_type>
requires bsl::is_convertible_v<ALLOC *, ALLOCATOR>
basic_string<CHAR_TYPE, CHAR_TRAITS, ALLOCATOR>(
basic_string<CHAR_TYPE, CHAR_TRAITS, ALLOCATOR>,
SZ,
SZ,
ALLOC*) -> basic_string<CHAR_TYPE, CHAR_TRAITS, ALLOCATOR>;