Utils.cs

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using System.Diagnostics.CodeAnalysis;
using System.Runtime.CompilerServices;
 
namespace System.Linq.Expressions;
 
internal static class Utils
{
    public static readonly object BoxedFalse = false;
 
    public static readonly object BoxedTrue = true;
 
    public static readonly object BoxedIntM1 = -1;
 
    public static readonly object BoxedInt0 = 0;
 
    public static readonly object BoxedInt1 = 1;
 
    public static readonly object BoxedInt2 = 2;
 
    public static readonly object BoxedInt3 = 3;
 
    public static readonly object BoxedDefaultSByte = (sbyte)0;
 
    public static readonly object BoxedDefaultChar = '\0';
 
    public static readonly object BoxedDefaultInt16 = (short)0;
 
    public static readonly object BoxedDefaultInt64 = 0L;
 
    public static readonly object BoxedDefaultByte = (byte)0;
 
    public static readonly object BoxedDefaultUInt16 = (ushort)0;
 
    public static readonly object BoxedDefaultUInt32 = 0u;
 
    public static readonly object BoxedDefaultUInt64 = 0uL;
 
    public static readonly object BoxedDefaultSingle = 0f;
 
    public static readonly object BoxedDefaultDouble = 0.0;
 
    public static readonly object BoxedDefaultDecimal = 0m;
 
    public static readonly object BoxedDefaultDateTime = default(DateTime);
 
    private static readonly ConstantExpression s_true = Expression.Constant(BoxedTrue);
 
    private static readonly ConstantExpression s_false = Expression.Constant(BoxedFalse);
 
    private static readonly ConstantExpression s_m1 = Expression.Constant(BoxedIntM1);
 
    private static readonly ConstantExpression s_0 = Expression.Constant(BoxedInt0);
 
    private static readonly ConstantExpression s_1 = Expression.Constant(BoxedInt1);
 
    private static readonly ConstantExpression s_2 = Expression.Constant(BoxedInt2);
 
    private static readonly ConstantExpression s_3 = Expression.Constant(BoxedInt3);
 
    public static readonly DefaultExpression Empty = Expression.Empty();
 
    public static readonly ConstantExpression Null = Expression.Constant(null);
 
    public static ConstantExpression Constant(bool value)
    {
        if (!value)
        {
            return s_false;
        }
        return s_true;
    }
 
    public static ConstantExpression Constant(int value)
    {
        return value switch
        {
            -1 => s_m1, 
            0 => s_0, 
            1 => s_1, 
            2 => s_2, 
            3 => s_3, 
            _ => Expression.Constant(value), 
        };
    }
 
    [DynamicDependency("Value", typeof(StrongBox<>))]
    [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:RequiresUnreferencedCode", Justification = "The field will be preserved by the DynamicDependency")]
    public static MemberExpression GetStrongBoxValueField(Expression strongbox)
    {
        return Expression.Field(strongbox, "Value");
    }
}