使用 foreach 循环——无法读取变量

Question

应该很简单，但事实并非如此。

这是我的代码：

string cases()
{
    string ret = "";
    string[] methods;

    methods = [__traits(derivedMembers,mixin("Math"))];
    foreach (string s; methods) ret ~= "case \"" ~ s ~ "\": return Math."~s~"(params);";

    methods = [__traits(derivedMembers,mixin("OtherClass"))];
    foreach (string s; methods) ret ~= "case \"" ~ s ~ "\": return OtherClass."~s~"(params);";

    return ret;
}

string execute(string what, string[] params)
{
    switch (what)
    {
        mixin(cases());
        default: break;
    }
    return "";
}

我想做的事：

const string[] arrayWithClassNames = ["Math","SomeClass"];
foreach (string s; arrayWithClassNames)
{
     methods = ...
     foreach ...
}

相当简单吧？问题是它抱怨：

variable 's' cannot be read at compile time. 

有什么想法吗？

Answer 1

要创建一个编译时循环，您需要遍历一个元组。试试这个：

alias classNames = TypeTuple!("Math","SomeClass");
foreach (string s; classNames)
{
    ...
}