DIP69 - Implement scope for escape proof references

[Nick Treleaven via Digitalmars-d]

On 05/12/2014 23:58, Walter Bright wrote:
>> 2) `scope ref` return values cannot be stored.
>>
>>      scope ref int foo();
>>      void bar(scope ref int a);
>>
>>      foo().bar();        // allowed
>>      scope tmp = foo();  // not allowed
>>      tmp.bar();
>
> Right

 From the DIP:

"The lifetime of a scope return value is the lifetime of an rvalue. It 
may not be copied in a way that extends its life."

With part of the example:

scope int* foo();
...
int* p = foo();       // Error, lifetime(p) is ∞

Maybe the error should be 'scope return value cannot be stored', because 
otherwise p could be inferred as scope.