digitalmars.D.bugs - [Issue 23021] New: [dip1000] infer return scope from pure nothrow
- d-bugmail puremagic.com (39/39) Apr 16 2022 https://issues.dlang.org/show_bug.cgi?id=23021
https://issues.dlang.org/show_bug.cgi?id=23021 Issue ID: 23021 Summary: [dip1000] infer return scope from pure nothrow Product: D Version: D2 Hardware: All OS: All Status: NEW Severity: enhancement Priority: P1 Component: dmd Assignee: nobody puremagic.com Reporter: dkorpel live.nl Currently, you can pass a scope pointer to a non-scope parameter if: - the called function is pure nothrow - there are no parameters with mutable indirections that can store pointers - the called function's return type has no pointers / `ref` ``` safe: bool deref(int* x) pure nothrow; void main() { int x; deref(&x); // allowed to pass scope pointer } ``` However, this doesn't work, because the third condition isn't met: ``` safe: int* identity(int* x) pure nothrow; void main() { int x; int* y = identity(&x); // y is now a scope pointer } ``` Since the first two conditions are met, the compiler could infer `return scope` on `identity` instead of `scope`. --
Apr 16 2022