问题描述
我想知道程序员何时使用函数 try 块.什么时候有用?
I'm wondering when programmers use function try blocks. When is it useful?
void f(int i)
try
{
if ( i < 0 )
throw "less than zero";
std::cout << "greater than zero" << std::endl;
}
catch(const char* e)
{
std::cout << e << std::endl;
}
int main() {
f(1);
f(-1);
return 0;
}
输出:(在ideone)
greater than zero
less than zero
正如有些人可能认为函数定义的语法不正确(因为语法看起来不熟悉)，我不得不说不，它不正确.它被称为函数尝试块.请参阅 C++ 标准中的 §8.4/1 [dcl.fct.def].
As some people might think that the syntax of function defintion is incorrect (because the syntax doesn't look familiar), I've to say that no its not incorrect. Its called function-try-block. See §8.4/1 [dcl.fct.def] in the C++ Standard.
推荐答案
您可以在构造函数中使用它来捕获初始化程序中的错误.通常，您不会发现这些错误，因此这是一个非常特殊的用途.
You use it in constructors to catch errors from initializers. Usually, you don't catch those errors, so this is a quite exceptional use.
否则，这是无用的:除非我被证明是错误的，
Otherwise, it is useless: unless I'm proven wrong,
void f() try { ... } catch (...) { ... }
严格等同于
void f() { try { ... } catch (...) { ... } }
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