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[BUG] Can not declare functions that return function pointers #1397
Description
Describe the bug
I copy pasted an example from wiki (https://github.com/hsutter/cppfront/wiki/Design-note:-Postfix-operators) to play with and it does not parse.
To Reproduce
Sample code:
f: (i: int) -> * (j: int) -> string = { return nullptr; }Result:
main.cpp2...
main.cpp2(1,25): error: missing ';' at end of declaration or '=' at start of initializer (at '->')
main.cpp2(1,1): error: unexpected text at end of Cpp2 code section (at 'f')
main.cpp2(1,0): error: parse failed for section starting here
Steps to reproduce the behavior:
Run as ./source/cppfront main.cpp2 -p with cppfront built from commit 5aa32ae.
Additional context
Would be nice if it got fixed with a unit test for something like this:
// C stdlib and POSIX function
void (*signal(int signum, void (*handler)(int)))(int)
// expected C++2 syntax
signal: (signum: int, handler: *(_: int) -> void) -> *(_: int) -> void
Activity
threeifbyair commentedon Jun 21, 2025
I took a look at this and reproduced your problem. I'll dig a little deeper, but in the meantime, here is a workaround:
intfuncptr: type == *(_: int) -> void;
signal: (signum: int, handler: intfuncptr) -> intfuncptr
My guess is that the compiler is getting confused by multiple -> operators, but that's just a guess for right now. (And it gets even more confused if you put *(_: int) -> void into parentheses.)
threeifbyair commentedon Jun 21, 2025
In case I don't come back to this, we have three different cases:
The first fails to parse. The second complains that the _ argument in the return value has not been initialized (?!). The third works fine.