On 12/09/2014 07:41, Ilya Yaroshenko wrote:
auto functionName(Range1, Range2)(Range1 r1, Ranger2) scope { import std.range; //imports are allowed enum MaxLength = 1024; //enums are allowed immutable A = [0.123, 0.456, 0.789]; // immutable and const are allowed bool isOdd (uint i) {return i%2;}static assert(isInputRange!Range1, Range1.stringof!~" is not InputRange"); int i; //Error, mutable data disallowed. immutable length = r1.length; //Error, can't use function parameters. } in { assert(!r1.empty); // we already know that r1 is InputRange and function have local imports! // can use std.range, MaxLength, A, isOdd }
I like this idea, I've wanted something like it to share an expression used in a template constraint with the function body - I suggest that constraints can use symbols defined in the 'scope' block too. As well as making template and contract code more DRY, it may also allow us to further reduce global imports where they are only used in template constraints.
