[cxx-abi-dev] Proposed ABI changes for new C++0x SFINAE rules

[David Vandevoorde]

On Jul 13, 2010, at 10:08 PM, John McCall wrote:

> On Jun 30, 2010, at 8:33 AM, David Vandevoorde wrote:
>> - We propose additional encodings for literals that can now appear in signatures.  nullptr is "LDn0E"; i.e., "a zero of type std::nullptr_t".  More interestingly, string literals are encoded as L<character type>E, where <character type> is the encoding of the (unqualified) underlying character type.  This has a few consequences for the demangler: It cannot actually reproduce the string, and it can only distinguish character literals from string literals after having seen the first character following the character type code.
> 
> Is this sufficient?  Overloading can be dependent on the length of the string, i.e. these are different templates:
>  template <class T> auto foo(T x) -> decltype(bar(x, "abc"));
>  template <class T> auto foo(T x) -> decltype(bar(x, "abcd"));

Good catch!

How about using:

	L <string type> E

?

That matches the (new) nullptr approach.  In addition to the string size, it also encodes the cv-qualifier, which ensures that we get distinct encodings for compilations with a mode where string literals are non-const.

	Daveed