ES.10:每次只定义一个名称
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.
每行一个声明的做法可以提高可读性,避免C/C++语法相关的错误。也可以为描写性行末注释留出空间。
char *p, c, a[7], *pp[7], **aa[10]; // yuck!Exception
A function declaration can contain several function argument declarations.
函数声明可以包含多个参数声明。
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 */ }
template <class InputIterator, class Predicate>
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);
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 2
double scalbn(double base, int exponent);
int a = 7, b = 9, c, d = 10, e = 3;
In a long list of declarators it is easy to overlook an uninitialized variable.
如果是一长串声明,很容易漏掉某个没有初始化的变量。
Enforcement(实施建议)
Flag variable and constant declarations with multiple declarators (e.g., int* p, q;)
标记包含多个变量和常数的声明语句。
原文链接
https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#es10-declare-one-name-only-per-declaration