P0849R8 auto(x): decay-copy in the language #5015
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@opensdh, please have a look. |
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Why me in this case? |
Because you wanted it: #4745 |
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Thanks for the reminder! |
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source/declarations.tex
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| @@ -1954,6 +1954,20 @@ | |||
| that contains a placeholder type, | |||
| \tcode{T} is the declared type of the non-type template parameter | |||
| and $E$ is the corresponding template argument. | |||
| \item | |||
| For an explicit type conversion\iref{expr.type.conv}, | |||
| \tcode{T} is \tcode{auto}. | |||
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So as to not just say "T is auto" without any hint why, @zygoloid suggests something like this:
[...]
Tis the specified type. [Note: Placeholder type deduction is only performed when the specified type isauto. --end note]
It's a bit more verbose, but helps the reader along a little. What do you think, @opensdh, @jensmaurer ?
Alternatively, for an even more radical change, see second comment.
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Moving discussion to separate pull request #5039.
source/expressions.tex
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| Otherwise, if the type is \tcode{auto}, | ||
| it is replaced by the type deduced for the variable \tcode{x} | ||
| in the invented declaration\iref{dcl.spec.auto}, | ||
| which is never interpreted as a function declaration: | ||
| \begin{codeblock} | ||
| auto x @\placeholder{init}@; | ||
| \end{codeblock} | ||
| , where \placeholder{init} is the initializer. | ||
| it is replaced by the type | ||
| determined by placeholder type deduction\iref{dcl.type.auto.deduct}. |
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Even more radical alternative:
Otherwise, if the type contains a placeholder type, it is replaced by the type
determined by placeholder type deduction\iref{dcl.type.auto.deduct}.
And then move the "shall" up to dcl.type.auto.deduct:
For an explicit type conversion,
Tis the specified type, which shall beauto.
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I agree with this direction (as implemented in #5039).
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Fixes #4979
Fixes cplusplus/papers#293