On Monday, 25 February 2019 at 15:26:33 UTC, Jonathan M Davis
wrote:
On Monday, February 25, 2019 5:47:47 AM MST Simen Kjærås via
String functions can't access the local scope, and thus can't
see Dummy. Using lambdas works. (string functions were
basically a workaround for no decent lambda syntax back in the
time when dinosaurs roamed the earth)
They're actually still useful in cases where you need to
compare lambdas (since you can't compare actual lambdas, but
you can compare strings), and in some cases, using a string
lambda with a function that accepts it is less verbose than
using a regular lambda, but in general, folks do tend to use
regular lambdas now that we have the more concise lambda syntax
- especially since string lambdas do have some annoying
limitations like this.
Lambdas can be compared, though:
static assert(__traits(isSame, a => a, i => i));
alias fn1 = a => a * 2;
alias fn2 = b => b * 2;
static assert(__traits(isSame, fn1, fn2));
There are limits, as specified on
https://dlang.org/spec/traits.html#isSame
--
Simen
