fork download

using System;
using System.Diagnostics;
using System.Linq.Expressions;
 
namespace SampleConsoleApp1
{
    static class StaticCast<TSource, TDestination>
    {
        private static Func<TSource, TDestination> cast = GenerateCast();
 
        private static Func<TSource, TDestination> GenerateCast()
        {
            var param = Expression.Parameter(typeof(TSource));
            var convert = Expression.Convert(param, typeof(TDestination));
            var lambda = Expression.Lambda<Func<TSource, TDestination>>(convert, param);
            return lambda.Compile();
        }
 
        public static TDestination Apply(TSource value) {
            return cast(value);
        }
    }
 
    class NumUpDownEx<T>
    {
        public decimal m_ud_value;
        public T Value
        {
            get { return StaticCast<decimal, T>.Apply(m_ud_value); }
        }
    }
 
    class Program
    {
        static void Main(string[] args)
        {
            var obj1 = new NumUpDownEx<int>();
            obj1.m_ud_value = 1234m;
            Console.WriteLine(1234 == obj1.Value);
            var obj2 = new NumUpDownEx<double>();
            obj2.m_ud_value = 3456.7m;
            Console.WriteLine((double)3456.7m == obj2.Value);
        }
    }
}
 

prog.cs(13,36): error CS1501: No overload for method `Parameter' takes `1' arguments
/usr/lib/mono/gac/System.Core/3.5.0.0__b77a5c561934e089/System.Core.dll (Location of the symbol related to previous error)
prog.cs(14,38): error CS1502: The best overloaded method match for `System.Linq.Expressions.Expression.Convert(System.Linq.Expressions.Expression, System.Type)' has some invalid arguments
/usr/lib/mono/gac/System.Core/3.5.0.0__b77a5c561934e089/System.Core.dll (Location of the symbol related to previous error)
prog.cs(14,38): error CS1503: Argument `#1' cannot convert `object' expression to type `System.Linq.Expressions.Expression'
prog.cs(15,37): error CS1502: The best overloaded method match for `System.Linq.Expressions.Expression.Lambda<System.Func<TSource,TDestination>>(System.Linq.Expressions.Expression, params System.Linq.Expressions.ParameterExpression[])' has some invalid arguments
/usr/lib/mono/gac/System.Core/3.5.0.0__b77a5c561934e089/System.Core.dll (Location of the symbol related to previous error)
prog.cs(15,37): error CS1503: Argument `#1' cannot convert `object' expression to type `System.Linq.Expressions.Expression'
prog.cs(16,27): error CS1061: Type `object' does not contain a definition for `Compile' and no extension method `Compile' of type `object' could be found (are you missing a using directive or an assembly reference?)
Compilation failed: 6 error(s), 0 warnings

Standard output is empty