On Monday, 17 August 2020 at 04:30:08 UTC, H. S. Teoh wrote:
On Mon, Aug 17, 2020 at 12:20:24AM +0000, Cecil Ward via
Digitalmars-d-learn wrote:
In a lambda, how do we know what types the arguments are? In
something
like
(x) => x * x
It's implemented as a template, whose argument types are
inferred based on usage context.
- there I just don’t get it at all. Can you write
(uint x) => x * x
Of course you can.
I’m lost.
[...]
If you're ever unsure of what the inferred type(s) are, you can
do replace the lambda with something like this:
(x) { pragma(msg, typeof(x)); return x*x }
which will print out the inferred type when the compiler
instantiates the lambda.
T
Ah! That’s the vital missing piece - I didn’t realise it was like
a template - I just thought it was an ordinary plain anonymous
function, not a generic. All makes sense now.
