static void Main(string[] args)
{
// This is allowed (where T : ClassB)
var templateClassInstance = new TemplateClass <ClassB>();
// This is also allowed (ClassC is successor of ClassB)
var templateClassInstance2 = new TemplateClass <ClassC>();
// This is invalid:
// var templateClassInstance3 = new TemplateClass<ClassA>();
// 'ClassA' cannot be used as type parameter 'T'
// There is no implicit reference conversion from 'ClassA' to 'ClassB'.
// These are allowed (where T : IClassable)
var templateClassConstrainedByInterface =
new TemplateClassConstrainedByInterface <ClassA>(new ClassA());
var templateClassConstrainedByInterface2 =
new TemplateClassConstrainedByInterface <ClassB>(new ClassB());
var templateClassConstrainedByInterface3 =
new TemplateClassConstrainedByInterface <StructureA>(new StructureA());
// This is allowed (where T : class)
var templateClassConstrainedByReference =
new TemplateClassConstrainedByReference <ClassA, ClassB>();
// This is allowed (where T : class)
var templateClassConstrainedByReference2 =
new TemplateClassConstrainedByReference <ClassA, ClassA>();
// This is invalid
//// var templateClassConstrainedByReference2 =
//// new TemplateClassConstrainedByReference<ClassB, ClassA>();
// 'ClassA' cannot be used as type parameter 'T2' in the generic type or method 'TemplateClassConstrainedByReference<T,T2>'.
// There is no implicit reference conversion from 'ClassA' to 'ClassB'.
// This is also invalid
//// var templateClassConstrainedByReference3 =
//// new TemplateClassConstrainedByReference<StructureA, StructureA>();
// 'StructureA' must be a reference type in order to use it as parameter 'T'
// in the generic type or method 'TemplateClassConstrainedByReference<T,T2>'
// This is allowed (where T : new())
var templateClassConstrainedByEmptyConstructor =
new TemplateClassConstrainedByEmptyConstructor <ClassA>();
// This is invalid
//// var templateClassConstrainedByEmptyConstructor2 =
//// new TemplateClassConstrainedByEmptyConstructor<ClassC>();
// 'ClassC' must be a non-abstract type with a public parameterless constructor
// in order to use it as parameter 'T' in the generic type or method 'TemplateClassConstrainedByEmptyConstructor<T>'
}
public static void Main()
{
// This is allowed (where T : ClassB)
var templateClassInstance = new TemplateClass<ClassB>();
// This is also allowed (ClassC is successor of ClassB)
var templateClassInstance2 = new TemplateClass<ClassC>();
// This is invalid:
//// var templateClassInstance3 = new TemplateClass<ClassA>();
// 'ClassA' cannot be used as type parameter 'T'
// There is no implicit reference conversion from 'ClassA' to 'ClassB'.
// These are allowed (where T : IClassable)
var templateClassConstrainedByInterface =
new TemplateClassConstrainedByInterface<ClassA>();
var templateClassConstrainedByInterface2 =
new TemplateClassConstrainedByInterface<ClassB>();
var templateClassConstrainedByInterface3 =
new TemplateClassConstrainedByInterface<StructureA>();
// This is allowed (where T : class)
var templateClassConstrainedByReference =
new TemplateClassConstrainedByReference<ClassA, ClassB>();
// This is invalid
//// var templateClassConstrainedByReference2 =
//// new TemplateClassConstrainedByReference<ClassB, ClassA>();
// 'ClassA' cannot be used as type parameter 'T2' in the generic type or method 'TemplateClassConstrainedByReference<T,T2>'.
// There is no implicit reference conversion from 'ClassA' to 'ClassB'.
// This is also invalid
//// var templateClassConstrainedByReference3 =
//// new TemplateClassConstrainedByReference<StructureA, StructureA>();
// 'StructureA' must be a reference type in order to use it as parameter 'T'
// in the generic type or method 'TemplateClassConstrainedByReference<T,T2>'
// This is allowed (where T : new())
var templateClassConstrainedByEmptyConstructor =
new TemplateClassConstrainedByEmptyConstructor<ClassA>();
// This is invalid
//// var templateClassConstrainedByEmptyConstructor2 =
//// new TemplateClassConstrainedByEmptyConstructor<ClassC>();
// 'ClassC' must be a non-abstract type with a public parameterless constructor
// in order to use it as parameter 'T' in the generic type or method 'TemplateClassConstrainedByEmptyConstructor<T>'
}
