Given a choice between a constructor call and a conversion function in C++17,
we prefer the constructor for direct-initialization and the conversion function
for copy-initialization, matching the behavior in C++14 and before. The
guaranteed copy elision rules were not intended to change the meaning of such
code (other than by removing unnecessary copy constructor calls).
This tweak will be raised with CWG.
llvm-svn: 317066
When selecting constructors for initializing an object of type T from a single
expression of class type U, also consider conversion functions of U that
convert to T (rather than modeling such conversions as calling a conversion
function and then calling a constructor).
This approach is proposed as the resolution for the defect, and is also already
implemented by GCC.
llvm-svn: 314231
When an object of class type is initialized from a prvalue of the same type
(ignoring cv qualifications), use the prvalue to initialize the object directly
instead of inserting a redundant elidable call to a copy constructor.
llvm-svn: 288866
Richard Smith