tmp/tmpgsypi94v/{from.md → to.md}
RENAMED
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@@ -6,11 +6,13 @@ with three-way comparison and make it easier to write the full
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complement of equality operations. **Effect on original feature:** For
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certain pairs of types where one is convertible to the other, equality
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or inequality expressions between an object of one type and an object of
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the other type invoke a different operator. Also, for certain types,
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equality or inequality expressions between two objects of that type
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-
become ambiguous.
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``` cpp
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struct A {
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operator int() const;
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};
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@@ -24,15 +26,19 @@ int check(A x, A y) {
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(10 == x) + // calls #1, previously selected #2
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(10 != x); // calls #1, previously selected #3
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}
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```
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**Change:** Overload resolution may change for equality operators
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[[expr.eq]]. **Rationale:** Support calling `operator==` with reversed
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order of arguments. **Effect on original feature:** Valid C++17 code
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that uses equality operators with conversion functions may be ill-formed
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or have different semantics in this revision of C++.
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``` cpp
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struct A {
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operator int() const { return 10; }
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};
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@@ -46,5 +52,7 @@ struct B {
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};
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B b1;
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bool eq = (b1 == b1); // ambiguous; previously well-formed
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```
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complement of equality operations. **Effect on original feature:** For
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certain pairs of types where one is convertible to the other, equality
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or inequality expressions between an object of one type and an object of
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the other type invoke a different operator. Also, for certain types,
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equality or inequality expressions between two objects of that type
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+
become ambiguous.
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+
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+
[*Example 1*:
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``` cpp
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struct A {
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operator int() const;
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};
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(10 == x) + // calls #1, previously selected #2
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(10 != x); // calls #1, previously selected #3
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}
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```
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+
— *end example*]
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+
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**Change:** Overload resolution may change for equality operators
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[[expr.eq]]. **Rationale:** Support calling `operator==` with reversed
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order of arguments. **Effect on original feature:** Valid C++17 code
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that uses equality operators with conversion functions may be ill-formed
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+
or have different semantics in this revision of C++.
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+
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[*Example 2*:
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``` cpp
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struct A {
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operator int() const { return 10; }
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};
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};
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B b1;
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bool eq = (b1 == b1); // ambiguous; previously well-formed
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```
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+
— *end example*]
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+
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