C#

Quote:

In Visual Basic and Visual C#, you can use the Assert method from either Debug or Trace, which are in the System.Diagnostics namespace. Debug class methods are not included in a Release version of your program, so they do not increase the size or reduce the speed of your release code.

private void FrmMain_Shown(object sender, EventArgs e)
    {
    ...
    string[] dataWithCounts = dataFromTextBox.GroupBy(d => d).Select(g =>$"{g.Key}({g.Count()})").ToArray();
    Debug.Assert(dataWithCounts.Count() != 3);
    }

IL_008c: call class [mscorlib]System.Collections.Generic.IEnumerable`1<!!1> [System.Core]System.Linq.Enumerable::Select<class [System.Core]System.Linq.IGrouping`2<string, string>, string>(class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0>, class [mscorlib]System.Func`2<!!0, !!1>)
IL_0091: call !!0[] [System.Core]System.Linq.Enumerable::ToArray<string>(class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0>)
IL_0096: stloc.1
IL_0097: ldloc.1
IL_0098: call int32 [System.Core]System.Linq.Enumerable::Count<string>(class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0>)
IL_009d: ldc.i4.3
IL_009e: ceq
IL_00a0: ldc.i4.0
IL_00a1: ceq
IL_00a3: call void [System]System.Diagnostics.Debug::Assert(bool)
IL_00a8: nop
IL_00a9: ret
} // end of method FrmMain::FrmMain_Shown

IL_0089: call class [mscorlib]System.Collections.Generic.IEnumerable`1<!!1> [System.Core]System.Linq.Enumerable::Select<class [System.Core]System.Linq.IGrouping`2<string, string>, string>(class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0>, class [mscorlib]System.Func`2<!!0, !!1>)
IL_008e: call !!0[] [System.Core]System.Linq.Enumerable::ToArray<string>(class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0>)
IL_0093: pop
IL_0094: ret

Quote:

a bit more basic, but sometimes that's exactly what you want.