d的异常

原文
用StdioException抛为何不能不抛?

nothrow void hello() {
  try {
    writeln("Hello, World!")
  } catch (StdioException) {}
}

这却可以?

nothrow void hello() {
  try {
    writeln("Hello, World!")
  } catch (Exception) {}
}

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d不验证异常,无法验证你调用的函数是否抛,要抓异常来满足不抛.

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函数抛异常,则不可能不抛.
函数属性推导.

import std.stdio;

class MyException : Exception {
    this(string msg) { super(msg); }
}

void throwing(int x) {
    if(x > 2) throw new MyException("Derp!");
    else writeln(x);
}

void noThrowing() nothrow {
    try {
        throwing(10);
    }//错误,throwing不是`不抛`函数.
    catch(MyException me) {}
}

void main()
{
    noThrowing();
}