Is there some place I can browse clang's implemented intrinsics and their precise syntax and semantics?
I'm currently trying to make sure the libc++ <type_traits> takes advantage of everything it can, such as the newly implemented __is_convertible_to and __is_base_of.
Thanks,
Howard
These should be (but aren't) all documented in LanguageExtensions.html
-Chris
Here's a list of intrinsics that I wish were documented but aren't. I'd document them myself, but it would be too easy for me to make incorrect assumptions about corner cases.
__is_union
__is_class
__is_enum
__has_trivial_constructor
__has_nothrow_constructor
__has_trivial_copy
__has_nothrow_copy
__has_trivial_assign
__has_nothrow_assign
__has_trivial_destructor
__has_virtual_destructor
__is_pod
__is_convertible_to
__is_base_of
And perhaps I've missed some, I'm not sure. For example I'd love to also see:
__underlying_type
__is_trivial
__is_trivially_copyable
__is_standard_layout
__is_literal_type
__is_nothrow_constructible
__is_trivially_constructible
__is_nothrow_assignable
__is_trivially_assignable
__is_destructible
__is_nothrow_destructible
__is_trivally_destructible
On a closely related note (and just fyi), the following paper is being prepared for the next meeting involving the constructor/assignment traits. This is still an early draft, though the proposed wording section is relatively mature:
http://home.roadrunner.com/~hinnant/traits.html
-Howard
The intention of all type trait intrinsics is to directly implement the corresponding standard library type trait. Any divergence is a bug in our implementation. Do any of these traits not have a corresponding type trait? If so, then another consideration is whether we actually want that intrinsic.
Sebastian
I've put up a design doc at:
http://libcxx.llvm.org/type_traits_design.html
This lists the traits we need for the std::lib, and compares it with the traits clang currently supplies. Some of the supplied traits are absolutely necessary, some are useful, others are unneeded, and some desperately needed traits are missing.
The missing traits are by no means the fault of the clang dev team. This list of traits reflects a traits-adjustment paper just voted in last week:
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3142.html
-Howard
Many of those missing traits are also needed for clang to parse MSVC
templated header file.
__is_base_of and __is_convertible_to notably.
I don't know if anybody is planning to work on this soon but if not
I'll do it after I am done with the anonymous redesign.