On Mon, Aug 15, 2011 at 7:43 PM, Jonathan Wakely <jwakely.gcc@xxxxxxxxx> wrote: > On 16 August 2011 00:30, Jeffrey Walton wrote: >> Hi All, >> >> I'm testing a custom allocator. The allocator works well with vector, >> but fails to link with basic_string (see below). >> >> I looked through Stroustrup and could not find info on _Alloc_hider. > > It starts with an underscore followed by an upper case letter, so it's > in the implementation namespace i.e. it's an implementation detail, so > you're not going to find it in a book. > > [SNIP] >> >> How does one one provided an allocator for use by a basic_string? > > By writing a type that meets the C++03 Allocator requirements, which > yours doesn't. > > If you look at the source you'll see that _Alloc_hider is a type > derived from the string's allocator_type, which is done to benefit > from the Empty Base Optimization. Since it is derived from the > string's allocator type, it is convertible to the allocator type,... Forgot to ask.... What are the C++03 retirements being violated? Or better, does GCC publish a specification? (I don't have a bootleg copy of the ISO/IEC copyrighted material). Jeff
