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[BUG] forward of capture $ crashes compiler #446
Description
Describe the bug
Enclosing capture in forward crashes compiler
Reproduction Code
main: () [[post: (forward c$) == 5]] //error
= {
c := 5;
:() = { (forward c$); }; //error
:() = { foo(forward c$); } (); //error - possibly valid usecase
}
foo: (forward x) = std::cout << x;
https://cpp2.godbolt.org/z/E4rqKW4cn
Version
latest (38aec57)
Command lines
cppfront/cppfront $1.cpp2 -p
clang++-15 -Icppfront/include $1.cpp -std=c++20 -o $1
Expected result
Diagnostic, probably disallowing forward with capture
Actual result
cppfront: source/cppfront.cpp:2712: void cpp2::cppfront::emit(cpp2::postfix_expression_node &, bool): Assertion `!current_args.back().ptoken' failed.
Aborted (core dumped)
Additional context
Assert line is https://github.com/hsutter/cppfront/blob/main/source/cppfront.cpp#L2712
This example shows forward can be written at call site.
Don't know if forward with capture makes sense.
Activity
realgdman commentedon May 10, 2023
Probably related:
x := (forward T<int>());assert on previous line.
cppfront: source/cppfront.cpp:2711: void cpp2::cppfront::emit(cpp2::postfix_expression_node &, bool): Assertion `n.expr->get_token()' failed.
JohelEGP commentedon Jun 2, 2023
Resolving #408 might happen to fix this.
JohelEGP commentedon Aug 6, 2023
This fails with the same error (https://cpp2.godbolt.org/z/49jcdPja6):
JohelEGP commentedon Nov 29, 2023
I tried to work around this by adding parentheses.
It simply lowers
forwardwithoutstd::.I suppose it's due to commit c39a94c (#77).
(forward (r$));lowers toreturn forward(_0);(https://cpp2.godbolt.org/z/YTP8vd61K).This could work with
std::forward_like<decltype(this)>semantics (given 4bd0c04#commitcomment-133309652)::(forward this) (forward c$).