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Re: [SG20] Difficulties in teaching the use of C++20 concepts

From: Nevin Liber <nevin_at_[hidden]>
Date: Sun, 22 Dec 2019 13:41:58 -0600
On Sun, Dec 22, 2019 at 11:48 AM Jon Kalb via SG20 <sg20_at_[hidden]>
wrote:

>
> There are two cases, what Herb calls “tracking” and “making the type
> stick.” I think I’d call them “tracking” and “fixing.” I think they should
> be spelled:
>
> auto x{expr}; // tracking - we want *x* to be whatever *expr returns*,
> even if it is changed by maintenance
>

The callee decides the type.


> auto x{type{expr}}; // fixing - we want *x* to be *type* regardless of
> what expr returns.
>

The caller decides the type.

I don’t see any other case.
>

The case that isn't here is the no surprises case when you want the caller
type and the callee type to match an explicitly mentioned type.
-- 
 Nevin ":-)" Liber  <mailto:nevin_at_[hidden] <nevin_at_[hidden]>>
+1-847-691-1404

Received on 2019-12-22 13:45:03