c++: Fix decltype(auto) deduction with rvalue ref [PR78209]
Here's a small deficiency in decltype(auto). [dcl.type.auto.deduct]/5: If the placeholder-type-specifier is of the form decltype(auto), [...] the type deduced for T is determined [...] as though E had been the operand of the decltype. So: int &&i = 0; decltype(auto) j = i; // should behave like int &&j = i; error We deduce j's type in do_auto_deduction via finish_decltype_type which takes an 'id' argument. Currently we compute 'id' as false, because stripped_init is *i (a REFERENCE_REF_P). But it seems to me we should rather set 'id' to true here, by looking through the REFERENCE_REF_P, so that finish_decltype_type DTRT. gcc/cp/ChangeLog: PR c++/78209 * pt.c (do_auto_deduction): If init is REFERENCE_REF_P, use its first operand. gcc/testsuite/ChangeLog: PR c++/78209 * g++.dg/cpp1y/decltype-auto1.C: New test.
Loading
Please register or sign in to comment