c++ - 在 C++ 中完成逻辑 AND 链中的所有函数调用

Question

可能重复：
C++ 中是否存在非短路逻辑“与”？
C++ 逻辑 & 运算符

我有类似这样的代码：

return ( check1() && check2() && check3() && check4() );

除了返回一个值（例如打印输出）之外，不同的检查函数还可以做其他事情。似乎这些checkX函数是按顺序运行的，只要一个返回 0，其余的就不会运行。这样做是有道理的。确保每个函数运行而不考虑其他返回值的最佳方法是什么（在 C++ 代码中）？

Answer 1

bool ret1 = check1();
bool ret2 = check2();
bool ret2 = check3();
bool ret4 = check4();

return (ret1 && ret2 && ret3 && ret4);

Answer 2

使用按位和运算符

return ( check1() & check2() & check3() & check4() );

这将在返回之前进行每个调用。

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Node: This is a hack and is not recommend.

Answer 3

一种解决方案可能是在 bool 变量中捕获每个函数的结果，并在所有 4 个变量上执行 chexk。

bool x1 = check1();
bool x2 = check2();
bool x3 = check3();
bool x4 = check4();
return (x1 && x2 && x3 && x3);

Answer 4

bool res = check1();
res &= check2();
res &= check3();
res &= check4();
return res;

Answer 5

If you don't care about the sequence in which the functions run, you could use:

return (check1() + check2() + check3() + check4()) == 4;

Another possibility would be to use pointers to functions, so you can invoke them in a loop:

typedef bool (*f)();

f checks[] = {check1, check2, check3, check4};

bool ret = true;
for (int i=0; i<4; i++)
     ret &= checks[i]();

return ret;

This doesn't help much for dealing with 4 functions, but if 4 is just a demo and there are really more (or there's a good possibility of that expanding), this makes it relatively easy to deal with a large number of functions when/if necessary.

If you cared more about conciseness than clarity, you could do something like this:

bool ret = check1();

return (ret &= check2()), (ret &= check3()), (ret & check4());