This should be a GCC bug. Full specialization should be allowed in any scope, including in class definition. According to CWG 727, [temp.expl.spec] paragraph 2 was changed from (emphasis mine) An explicit specialization shall be declared in a namespace enclosing the specialized template. An explicit specialization whose declarator-id or class-head-name is not qualified shall be … Read more
This is still undefined behavior (UB) as per expr.compound: The postfix-expression is sequenced before each expression in the expression-list and any default argument. The initialization of a parameter, including every associated value computation and side effect, is indeterminately sequenced with respect to that of any other parameter. (emphasis mine) This means that the postfix expression … Read more
In this particular case, the calls are legal. Section 6.7.6.3p15 of the C standard spells out what makes two function type compatible (relevant part in bold): For two function types to be compatible, both shall specify compatible return types. Moreover, the parameter type lists, if both are present, shall agree in the number of parameters … Read more
No guarantee whatsoever. [string.cons]/36 defines assigning a const char* to an std::string in term of a move-assignment, whose definition is: [string.cons]/32 basic_string& operator=(basic_string&& str) noexcept(/*…*/) Effects: Move assigns as a sequence container, except that iterators, pointers and references may be invalidated. This shows that the Committee let the implementation choose freely between an invalidating operation … Read more
[extern.names] 3 Each name from the C standard library declared with external linkage is reserved to the implementation for use as a name with extern “C” linkage, both in namespace std and in the global namespace. Note that this paragraph reserves the name itself. So aliasing time in the global namespace violates this contract.
In C, the maximum value for an unsigned integer must be in the form1: 2N – 1. Thus all value bits of the value UINT_MAX will be set to 1. There may be padding bits, whose values are unspecified. 1 (Quoted from: ISO/IEC 9899:201x 6.2.6.2 Integer types 1) For unsigned integer types other than unsigned … Read more
I believe Clang is correct to produce this error: The [temp.inst] section of the C++ standard in paragraph 10 says: If a function template or a member function template specialization is used in a way that involves overload resolution, a declaration of the specialization is implicitly instantiated (14.8.3). Forming the implicit conversion sequence necessary to … Read more
According to overload resolution, there are two viable functions: The specialization of the global operator|-template with deduced arguments and the specialization of the member operator function template. Both have the same signature – the member function template has an implicit object parameter of type Alice const& (see ยง13.3.1/4). So both viable functions (after template argument … Read more
The cluttered structure of C11 types resulting from the second step of the question can be simplified by removal/reduction of less important nodes and delegating some redundant/subsidiary information to be presented by other means. I propose the following five-step algorithm for that: Removal of all extended integer types (strictly conforming implementation assumed); Reduction of the … Read more
Overload resolution is fun like this. {a} has exact match rank for initializing (a temporary for) the const A& parameter, which outcompetes the user-defined conversion B(const A&) as a realization of {a}. This rule was added in C++14 to resolve ambiguities in list-initialization (along with adjustments for aggregates). Note that the notional temporary is never … Read more