C++核心准则ES.10:每次只定义一个名称

C++核心准则ES.10:每次只定义一个名称

ES.10: Declare one name (only) per declaration

ES.10:每次只定义一个名称

Reason（原因）

One declaration per line increases readability and avoids mistakes related to the C/C++ grammar. It also leaves room for a more descriptive end-of-line comment.

Example, bad（反面示例）

char *p, c, a[7], *pp[7], **aa[10]; // yuck!Exception

A function declaration can contain several function argument declarations.

Exception（例外）

A structured binding (C++17) is specifically designed to introduce several variables:

结构化绑定（C++17）是为引入多个变量而特别设计的。

auto [iter, inserted] = m.insert_or_assign(k, val);if (inserted) { /* new entry was inserted */ }

Example（示例）

template bool any_of(InputIterator first, InputIterator last, Predicate pred);

or better using concepts:

更好的选择是使用concepts：

bool any_of(InputIterator first, InputIterator last, Predicate pred);

Example（示例）

double scalbn(double x, int n); // OK: x * pow(FLT_RADIX, n); FLT_RADIX is usually 2

or（或者）:

double scalbn( // better: x * pow(FLT_RADIX, n); FLT_RADIX is usually 2 double x, // base value int n // exponent);

or（又或者）:

// better: base * pow(FLT_RADIX, exponent); FLT_RADIX is usually 2double scalbn(double base, int exponent);

Example（示例）

int a = 7, b = 9, c, d = 10, e = 3;

In a long list of declarators it is easy to overlook an uninitialized variable.

Enforcement（实施建议）

Flag variable and constant declarations with multiple declarators (e.g., int* p, q;)

原文链接

​​https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#es10-declare-one-name-only-per-declaration​​

觉得本文有帮助？欢迎点赞并分享给更多的人。

版权声明：本文内容由网络用户投稿，版权归原作者所有，本站不拥有其著作权，亦不承担相应法律责任。如果您发现本站中有涉嫌抄袭或描述失实的内容，请联系我们jiasou666@gmail.com 处理，核实后本网站将在24小时内删除侵权内容。