C++核心准则ES.105:避免被0除

ES.105: Don't divide by zero

ES.105:避免被0除

Reason（原因）

The result is undefined and probably a crash.

结果无定义，很可能会导致程序崩溃。

Note（注意）

This also applies to %.

本规则也适用于取余运算。

Example, bad（反面示例）

double divide(int a, int b)
{
    // BAD, should be checked (e.g., in a precondition)
    return a / b;
}

Example, good（范例）

double divide(int a, int b)
{
    // good, address via precondition (and replace with contracts once C++ gets them)
    Expects(b != 0);
    return a / b;
}

double divide(int a, int b)
{
    // good, address via check
    return b ? a / b : quiet_NaN<double>();
}

Alternative: For critical applications that can afford some overhead, use a range-checked integer and/or floating-point type.

可选项：对于能够承受一定代价的要求严格的应用，可以考虑使用带有范围检查的整数或者浮点数。

Enforcement（实施建议）

• Flag division by an integral value that could be zero
• 标记可能为零的整数除数。

原文链接 https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#es105-dont-divide-by-zero