C++核心准则T.150:用static_assert检查类和概念的匹配性

T.150: Check that a class matches a concept using static_assert

T.150:用static_assert检查类和概念的匹配性

Reason（原因）

If you intend for a class to match a concept, verifying that early saves users pain.

如果你希望一个类和概念相匹配，尽早地检查可以减轻用户的痛苦。

Example（示例）

class X {
public:
    X() = delete;
    X(const X&) = default;
    X(X&&) = default;
    X& operator=(const X&) = default;
    // ...
};

Somewhere, possibly in an implementation file, let the compiler check the desired properties of X:

在某处，在实现文件中也可以，让编译器检查X的期望属性：

static_assert(Default_constructible<X>);    // error: X has no default constructor
static_assert(Copyable<X>);                 // error: we forgot to define X's move constructor

Enforcement（实施建议）

Not feasible.

不可行。

原文链接

https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#t150-check-that-a-class-matches-a-concept-using-static_assert