On Sunday, 22 May 2016 at 19:29:59 UTC, Meta wrote:
Const *is* necessary to prevent _myVar being written to through
code like:
f.myVar = 4;
Of course this isn't necessary for value types, but for
reference types.
I was referring specifically to marking the function const, not
the return type. Marking the return type const is highly
context-dependent. It's perfectly reasonable to return a
non-const class reference from a getter property. As long as the
internal reference is private, it isn't going to be overwritten
externally without a setter property. I don't see how it could be
considered necessary. For a pointer, sure, to prevent
*(bar.fooVer) = Foo(10). But for class references it's only
necessary if you don't want the returned instances members to be
modified.
It's also useful for value types, IMO, for preventing someone
from doing this:
f.myVar = 4;
And wondering why the code has no effect.
The compiler already gives an error message describing the
problem:
Error: function mod.Foo.myVar () is not callable using argument
types (int)
How does const help here?
