d的自動域問題

​​原文​​

auto screen = executeShell(cmdLine);
auto s;//這樣聲明?
 //無法推導`"s"`的類型.
//從`getPath`的傳回類型來看,可能是`string[]`.
//應該這樣
string[] s;
...
{
    s = screen.output.findSplit("REG_SZ");
}

//但不編譯.

string[] getPath(string cmdLine)
{
    auto screen = executeShell(cmdLine);

    if (screen.status != 0)
    {
        writeln(cmdLine, " failed");
    }
    else
    {
        writeln("screen.output = ", screen.output);
        auto s = screen.output.findSplit("REG_SZ");
        writeln("s[0] = ", s[0]);
        writeln("s[1] = ", s[1]);
        writeln("s[2] = ", s[2]);
    }
    return (s.split(';'));  // 未定義s
}      

string[] getPath(string cmdLine)
{
    import std.exception : enforce;

    auto screen = executeShell(cmdLine);
    enforce(screen.status == 0, format!"%s failed:\n%s"(cmdLine, screen.output));
//確定
    writeln("screen.output = ", screen.output);
    //後面略....
}      

string[] getPath(string cmdLine)
{
    string[] result;
    auto screen = executeShell(cmdLine);

    if (screen.status != 0)
    {
        writeln(cmdLine, " failed");
        return null;  // 在此(`無效`轉數組)
    }
    else
    {
        // ...
        // 現在傳回s定義的.
        return (s.split(';'));
    }
}