[PATCH] D67113: ICK_Function_Conversion is a third kind conversion

[Aaron Puchert via Phabricator via cfe-commits]

aaronpuchert added a comment.
Herald added a subscriber: danielkiss.

In D67113#2244463 <https://reviews.llvm.org/D67113#2244463>, @aaron.ballman wrote:

> There may be a deeper issue here in that there are four standard conversion sequences, not three: http://eel.is/c++draft/conv#1, but otherwise this change seems correct to me (function conversion is certainly not in the first group).

It seems we've collapsed the third and fourth kind into one, I wonder if that makes a difference. This can even be observed in the AST:

  void f() noexcept;
  void (*const fp)() = f;
  //     VarDecl fp 'void (*const)()' cinit
  // (2) `-ImplicitCastExpr 'void (*const)()' <NoOp>
  // (1)   `-ImplicitCastExpr 'void (*)() noexcept' <FunctionToPointerDecay>
  //         `-DeclRefExpr 'void () noexcept' lvalue Function 'f' 'void () noexcept'

where (1) is a first kind conversion, and (2) a combined third and fourth kind conversion. Since both are essentially no-ops (see also D67112 <https://reviews.llvm.org/D67112>), it probably doesn't make sense to go into more detail.

> Do you have a test case which can exercise this change?

Nope, just discovered this while reading the code. This should be unreachable, so it would be bad if I could observe a change.


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  https://reviews.llvm.org/D67113/new/

https://reviews.llvm.org/D67113