`std.format.format!`的纯版本？

import std.format;
import std.string;
import std.conv;

string pureFormat(string formatString, Args...)(Args args)
{
    string result;
    size_t argIndex = 0;
    size_t formatIndex = 0;
    size_t formatLength = formatString.length;

    while (formatIndex < formatLength)
    {
        if (formatString[formatIndex] == '{' && formatString[formatIndex + 1] == '}')
        {
            if (argIndex >= args.length)
                throw new Exception("Not enough arguments for format string");

            result ~= to!string(args[argIndex]);
            argIndex++;
            formatIndex += 2;
        }
        else
        {
            result ~= formatString[formatIndex];
            formatIndex++;
        }
    }

    return result;
}

import std.stdio;

void main()
{
    int num = 42;
    string name = "Alice";
    writeln(pureFormat("Number: {}, Name: {}", num, name));
}

Number: 42, Name: Alice