generic function that is called with different generic types cannot infer correct generic type in sub call

[Casper64]

Describe the bug

In the following code V cannot determine what generic type should be passed to double_array(mut typ) and always uses the last used type.

The functions are generated, but the wrong generic function is used.

module main

pub fn generic_caller[T]() !T {
	mut typ := T{}
	$if T is $array {
		double_array(mut typ)
		return typ
	} $else {
		return error('not an array!')
	}
}

fn double_array[T](mut typ []T) {
	println('setting array of type ${T.typ}')
	for _ in 0 .. 2 {
		el := T{}
		typ << el
	}
}

pub struct User {
	name string
	age  int
}

pub struct Employee {
	id  int
	job string
}

fn main() {
	println('idx of User ${typeof[User]().idx}')

	users := generic_caller[[]User]()!
	println('users: ${users}')

	println('idx of Employee ${typeof[Employee]().idx}')
	// works if you comment out the following line
	employees := generic_caller[[]Employee]()!
	println('emplyees: ${employees}')
}

Reproduction Steps

>  v -cg run infer_array.v 

Expected Behavior

no errors

Current Behavior

> v -cg run infer_array.v 
idx of User 97
setting array of type 98
7ff826e9b649 : at ???: RUNTIME ERROR: invalid memory access
/tmp/v_1000/infer_array.13578371958434614598.tmp.c:9757: by string_clone
/tmp/v_1000/infer_array.13578371958434614598.tmp.c:11823: by StrIntpData_process_str_intp_data
/tmp/v_1000/infer_array.13578371958434614598.tmp.c:12256: by str_intp
/tmp/v_1000/infer_array.13578371958434614598.tmp.c:2145: by indent_main__User_str
/tmp/v_1000/infer_array.13578371958434614598.tmp.c:2104: by indent_Array_main__User_str
/tmp/v_1000/infer_array.13578371958434614598.tmp.c:2098: by Array_main__User_str
/tmp/v_1000/infer_array.13578371958434614598.tmp.c:12607: by main__main
/tmp/v_1000/infer_array.13578371958434614598.tmp.c:12653: by main

Possible Solution

I tried to fix it and found that node.concrete_types is correctly inferred for double_array in the checker stage, but this is not present in cgen.

Additional Information/Context

C code:

Array_main__User main__generic_caller_T_Array_main__User(void) {
	Array_main__User typ = __new_array_with_default(0, 0, sizeof(main__User), 0);
	#if 0
	{
	}
	#elif 1
	{
		main__double_array_T_main__Employee(&/*arr*/typ);
	}
	#endif
	return typ;
}
Array_main__Employee main__generic_caller_T_Array_main__Employee(void) {
	Array_main__Employee typ = __new_array_with_default(0, 0, sizeof(main__Employee), 0);
	#if 0
	{
	}
	#elif 1
	{
		main__double_array_T_main__Employee(&/*arr*/typ);
	}
	#endif
	return typ;
}

V version

V 0.4.1 V 0.4.1 a685088

Environment details (OS name and version, etc.)

V full version: V 0.4.1 a685088
OS: linux (WSL 2)

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[felipensp]

Already fixed.