Can we have a candy of params constructor to ValueTuple?

[qaqz111]

For example:

public static void Log((string format, params object[] args) log,
    [CallerFilePath] string file = "",
    [CallerLineNumber] int line = 0,
    [CallerMemberName] string func = "")
{
    logger.Log(new LogEventInfo(log.level, logger.Name, null, log.message, log.args)
       .SetCallerInfo(file, line, func));
}

Without this, we can only archieve it like this:

public static void LogF<T1, T2>(this Logger logger, (LogLevel level, string message, T1 arg1, T2 arg2) log,
    [CallerFilePath] string file = "",
    [CallerLineNumber] int line = 0,
    [CallerMemberName] string func = "")
{
    logger.Log(new LogEventInfo(log.level, logger.Name, null, log.message, new[]{log.arg1, log.arg2})
       .SetCallerInfo(file, line, func));
}

public static void LogF<T1, T2, T3>(this Logger logger, (LogLevel level, string message, T1 arg1, T2 arg2, T3 arg3) log,
    [CallerFilePath] string file = "",
    [CallerLineNumber] int line = 0,
    [CallerMemberName] string func = "")
{
    logger.Log(new LogEventInfo(log.level, logger.Name, null, log.message, new[]{log.arg1, log.arg2, log.arg3})
       .SetCallerInfo(file, line, func));
}

//...

public static void LogF<T1, ..., T20>(this Logger logger, (LogLevel level, string message, T1 arg1, ..., T20 arg20) log,
    [CallerFilePath] string file = "",
    [CallerLineNumber] int line = 0,
    [CallerMemberName] string func = "")
{
    logger.Log(new LogEventInfo(log.level, logger.Name, null, log.message, new[]{log.arg1, ..., log.arg20})
       .SetCallerInfo(file, line, func));
}

So, this is an usage of mixing params parameters and optional parameters when can not simply overload.

There are some related post on Github and StackOverflow:

• https://stackoverflow.com/questions/24936586/mixing-optional-parameters-and-params-when-cant-simply-overload
• Is there a way to get separate parts, for example source filename only without linenumber, from ${callsite}? NLog/NLog#2155

[HaloFour]

That doesn't work in C# without actually generating overloads for every possibly arity of tuple elements. Those tuple types are completely different and incompatible types.

[qaqz111]

Ya... I've got confused with usage of C++ macro and templates.

Just forget it :p

[HaloFour]

See #339 and dotnet/roslyn#5058.