Optional type information on local constants.

[davor-skontra]

At the moment it is possible to prefix a local variable with var and the type information is inferred from the assignment:

For example:

private void SomeMethod() {
    var foo = 1;
}

However when declaring local constants it is necessary to also write a type. Like here

private void SomeMethod() {
   const float baz = 2f;

   var foo = 1;
}

This feels a bit inconsistent. Maybe const baz = 2f; should be allowed for local constants, that way we could write

private void SomeMethod() {
    const baz = 2f;

    var foo = 1;
}

This would be both more constant and convenient. Additionally it would encourage using immutable values when possible.

[ufcpp]

#106

[Richiban]

See also #188 which would allow readonly locals (with a shorthand for readonly var) that would be applicable in all cases, not just constants.

[DavidArno]

And further, as per the discussion in #188, using let to be another way of expressing readonly var allows us to then say:

private void SomeMethod() 
{
   let baz = 2f; // readonly, ie constant
   let bar = new C(); // readonly, ie constant
   var foo = 1; // mutable
}

thus we get a consistent way of expressing local "constants" for all types, not just those allowed with the const keyword.

[john-h-k]

Personally I don't see the value in this. Constant locals must be of type bool, byte, sbyte, ushort, short, uint, int, ulong, long, float, double, decimal, char, string. None of these are particularly long or complex keywords, and const modifier isn't used anywhere near as regularly as non const locals, so saving ~5 chars doesn't seem worth it

[HekiShavik]

But @john-h-k take a look at enums then:

const TravellerBase.TravellerType typeFilter = TravellerBase.TravellerType.Adult | TravellerBase.TravellerType.Youth;

versus

const typeFilter = TravellerBase.TravellerType.Adult | TravellerBase.TravellerType.Youth;

It's definitely worth it in my oppinion.

[YairHalberstadt]

Closing as duplicate of #106