https://issues.dlang.org/show_bug.cgi?id=13710
Issue ID: 13710
Summary: Invariants not enforced on methods from alias this
Product: D
Version: D2
Hardware: x86_64
OS: Windows
Status: NEW
Severity: enhancement
Priority: P1
Component: DMD
Assignee: [email protected]
Reporter: [email protected]
When you do "alias this" and have an invariant, any
methods that are forwarded to the aliased member do not invoke
your invariant methods.
This prevents me from writing a really sleek 10-liner to the tune
of:
struct ValueRestrictedInteger(int lowerBound, int upperBound) {
int value;
alias value this;
this (int rhs) { value = rhs; }
invariant() {
assert (value >= lowerBound && value <= upperBound);
}
void forDemonstrationOnly() {}
}
unittest {
ValueRestrictedInteger!(0, 100) x = 0;
x += 10;
x -= 100; //This works, but I don't think it should
x.forDemonstrationOnly(); //This causes the assertion to fire
ValueRestrictedInteger!(0, 100) y = -100; //This also would hit
the assertion
}
Forum post on same topic:
http://forum.dlang.org/thread/[email protected]
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