private void CoreFmt <T0, T1, T2>(ref StringMaker sm, IFormatProvider?provider, T0 arg0, T1 arg1, T2 arg2, ReadOnlySpan <object?> args)
{
var literalIndex = 0;
foreach (var segment in _segments)
{
int literalCount = segment.LiteralCount;
if (literalCount > 0)
{
// the segment has some literal text
sm.Append(LiteralString.AsSpan(literalIndex, literalCount));
literalIndex += literalCount;
}
var argIndex = segment.ArgIndex;
if (argIndex >= 0)
{
// the segment has an arg to format
switch (argIndex)
{
case 0:
AppendArg(ref sm, arg0, segment.ArgFormat, provider, segment.ArgWidth);
break;
case 1:
AppendArg(ref sm, arg1, segment.ArgFormat, provider, segment.ArgWidth);
break;
case 2:
AppendArg(ref sm, arg2, segment.ArgFormat, provider, segment.ArgWidth);
break;
default:
AppendArg(ref sm, args[argIndex - 3], segment.ArgFormat, provider, segment.ArgWidth);
break;
}
}
}
}
/// <summary>
/// Formats a string with arguments.
/// </summary>
/// <param name="destination">Where to write the resulting string.</param>
/// <param name="charsWritten">The number of characters actually written to the destination span.</param>
/// <param name="provider">An optional format provider that provides formatting functionality for individual arguments.</param>
/// <param name="args">Arguments to use in the formatting operation.</param>
/// <returns>True if there was enough room in teh destination span for the resulting string.</returns>
public bool TryFormat(Span <char> destination, out int charsWritten, IFormatProvider?provider, params object?[]?args)
{
CheckNumArgs(0, args);
if (NumArgumentsNeeded == 0)
{
if (destination.Length < LiteralString.Length)
{
charsWritten = 0;
return(false);
}
LiteralString.AsSpan().CopyTo(destination);
charsWritten = LiteralString.Length;
return(true);
}
return(args !.Length switch
{
1 => TryFmt <object?, object?, object?>(destination, out charsWritten, provider, args[0], null, null, null),
2 => TryFmt <object?, object?, object?>(destination, out charsWritten, provider, args[0], args[1], null, null),
3 => TryFmt <object?, object?, object?>(destination, out charsWritten, provider, args[0], args[1], args[2], null),
_ => TryFmt <object?, object?, object?>(destination, out charsWritten, provider, args[0], args[1], args[2], args.AsSpan(3)),
});
