ufcpp

class Program
{
    static void X(bool x) { }
    static void X(bool x, bool y) { }
    static bool A<T1, T2>(int x) => true;
    class B { }
    class C { }

    static void Main()
    {

ufcpp

using System.Globalization;
using System.Runtime.CompilerServices;

Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;

static string m(bool condition) => string.Create(
    CultureInfo.GetCultureInfo("fr-fr"), 
    $"direct: {1.5} or {1:c}, nested: {If(condition, $"{1.5}", $"{1:C}")}");

Console.WriteLine(m(true));

ufcpp

using System.Buffers;

public interface IDefaultSpanFormattable : ISpanFormattable
{
    string IFormattable.ToString(string? format, IFormatProvider? formatProvider)
    {
        var buffer = (stackalloc char[512]);
        if (TryFormat(buffer, out var charsWritten, format, formatProvider))
        {
            return new string(buffer[..charsWritten]);

ufcpp

using System.Diagnostics.CodeAnalysis;
using System.Runtime.CompilerServices;

var nodes = new Node<string>[]
{
    new("a0", 2),
    new("a1", 5),
    new("a2", 1),
    new("a3", -2),
    new("a4", 3),

ufcpp

using System.Text.RegularExpressions;
using System.Windows;

class Program
{
    [STAThread]
    static void Main()
    {
        var x = Clipboard.GetText();

ufcpp

using System.Globalization;

var items = new[]
{
    "ABc",
    "Abc",
    @"A\c",
};

// ASCII コード順。

ufcpp

var a = new[] {
				0,
1,
2,
    3,
    4,
    5,
    6,
    7,
    8,

ufcpp

// see https://stackoverflow.com/questions/6643076/tarjan-cycle-detection-help-c-sharp
// tests simple model presented on https://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm
using System.Runtime.InteropServices;

var cycles = CycleDetector.Detect(
    (1, 2),
    (2, 3),
    (3, 1),
    (4, 3),
    (4, 5),

ufcpp

// Unicode 8.0
int ᏸ = 8; // U+13F8, Cherokee Small Letter Ye

// Unicode 9.0
int Ɪ = 9; // U+A7AE, Small Captital I

// Unicode 10.0
int ৼ = 10; // U+09FC, Bengali Letter Vedic Anusvara

// Unicode 11.0

ufcpp

Console.WriteLine("123".ParseOrNull<int>());
Console.WriteLine("1a3".ParseOrNull<int>());

static class Ex
{
    public static T? ParseOrNull<T>(this string? s, IFormatProvider? provider = null)
        where T : struct, IParsable<T>
        => T.TryParse(s, provider, out var value) ? value : null;
}