tmp/tmpcg6bxfoa/{from.md → to.md}
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### Secondary comparison operators <a id="class.compare.secondary">[[class.compare.secondary]]</a>
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A *secondary comparison operator* is a relational operator [[expr.rel]]
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or the `!=` operator. A defaulted operator function [[over.binary]] for
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a secondary comparison operator `@` shall have a declared return type
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`bool`.
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The operator function with parameters `x` and `y` is defined as deleted
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if
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- overload resolution [[over.match]], as applied to `x @ y`, does not
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result in a usable candidate, or
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- the candidate selected by overload resolution is not a rewritten
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candidate.
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Otherwise, the operator function yields `x @ y`. The defaulted operator
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function is not considered as a candidate in the overload resolution for
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the `@` operator.
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[*Example 1*:
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``` cpp
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struct HasNoLessThan { };
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struct C {
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friend HasNoLessThan operator<=>(const C&, const C&);
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bool operator<(const C&) const = default; // OK, function is deleted
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};
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```
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— *end example*]
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