tmp/tmpg_qs76qv/{from.md → to.md}
RENAMED
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@@ -159,19 +159,20 @@ v2[3] = dcomplex(7,8); // Array<dcomplex>::operator[]
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— *end example*]
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#### Deduction guides <a id="temp.deduct.guide">[[temp.deduct.guide]]</a>
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Deduction guides are used when a *template-name*
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specifier
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guides are not found by name
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-
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-
deduction guides declared for
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``` bnf
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deduction-guide:
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explicit-specifierₒₚₜ template-name '(' parameter-declaration-clause ')' '->' simple-template-id ';'
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```
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[*Example 1*:
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``` cpp
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@@ -190,11 +191,13 @@ S x{A()}; // x is of type S<short, int>
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```
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— *end example*]
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The same restrictions apply to the *parameter-declaration-clause* of a
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deduction guide as in a function declaration [[dcl.fct]]
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*simple-template-id* shall name a class template specialization. The
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*template-name* shall be the same *identifier* as the *template-name* of
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the *simple-template-id*. A *deduction-guide* shall inhabit the scope to
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which the corresponding class template belongs and, for a member class
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template, have the same access. Two deduction guide declarations for the
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@@ -271,11 +274,10 @@ class template definition.
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``` cpp
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template<class T> struct A {
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enum E : T;
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};
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A<int> a;
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template<class T> enum A<T>::E : T { e1, e2 };
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A<int>::E e = A<int>::e1;
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```
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— *end example*]
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— *end example*]
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#### Deduction guides <a id="temp.deduct.guide">[[temp.deduct.guide]]</a>
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+
Deduction guides are used when a *template-name* or
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*splice-type-specifier* appears as a type specifier for a deduced class
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type [[dcl.type.class.deduct]]. Deduction guides are not found by name
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lookup. Instead, when performing class template argument deduction
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[[over.match.class.deduct]], all reachable deduction guides declared for
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the class template are considered.
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``` bnf
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deduction-guide:
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explicit-specifierₒₚₜ template-name '(' parameter-declaration-clause ')' '->' simple-template-id requires-clauseₒₚₜ ';'
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```
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[*Example 1*:
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``` cpp
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```
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— *end example*]
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The same restrictions apply to the *parameter-declaration-clause* of a
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deduction guide as in a function declaration [[dcl.fct]], except that a
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generic parameter type placeholder [[dcl.spec.auto]] shall not appear in
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the *parameter-declaration-clause* of a deduction guide. The
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*simple-template-id* shall name a class template specialization. The
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*template-name* shall be the same *identifier* as the *template-name* of
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the *simple-template-id*. A *deduction-guide* shall inhabit the scope to
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which the corresponding class template belongs and, for a member class
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template, have the same access. Two deduction guide declarations for the
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``` cpp
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template<class T> struct A {
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enum E : T;
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};
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template<class T> enum A<T>::E : T { e1, e2 };
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A<int>::E e = A<int>::e1;
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```
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— *end example*]
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