https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114242
Bug ID: 114242
Summary: Coroutine with lambda-coroutine and operator new does
not compile
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: src at andyf dot de
Target Milestone: ---
Hello,
the following code is accepted by Clang but rejected by g++ and MSVC:
https://compiler-explorer.com/z/7P548dGG3
Once the lambda inside the coroutine isn't used, the code compiles with all
three compilers.
My reading of http://eel.is/c++draft/dcl.fct.def.coroutine#9.1 is that the
custom operator new should be picked in all cases.
G++'s error:
```
<source>: In lambda function:
<source>:54:15: error: 'operator new' is provided by
'std::__n4861::__coroutine_traits_impl<Generator, void>::promise_type' {aka
'Generator::promise_type'} but is not usable with the function signature
'coro(std::span<unsigned char>)::<lambda(std::span<unsigned char>)>'
54 | auto lamb = [](std::span<unsigned char>) -> Generator {
| ^
```
suggests that the compiler tries to look up an operator new with only size as
an argument.
