What is the difference between static_cast and Implicit_cast?
What is implicit_cast? when should I prefer implicit_cast rather than static_cast? ...
implicit-cast
C++ rely on implicit conversion to bool in conditions?
I found the following rule in a coding standards sheet : Do not rely on implicit conversion to bool in conditions. if (ptr) // wrong if (ptr != NULL) // ok How reasonable/usefull is this rule? How much overload on the compiled code? ...
Why is implicit conversion allowed from superclass to subclass?
Can someone tell me why the line with "//Compiles" compiles, and why the line with "//Doesn't Compile" does not? I don't understand why A would be implicitly convertible to B, not the other way round. public class SomeClass { static public void Test() { AClass a = new AClass(); BClass b = new BClass(); a = b; // Compiles b...
Getting rid of error C2243
Is it possible to getting rid of error C2243? class B {}; class D : protected B {}; D d; B *p = &d; // conversion from 'D *' to 'B &' exists, but is inaccessible I had this error in my app and at the end I've managed to compile it by making an explicit conversion: D d; B *p = (B*)&d; I can't understand why by making class D inhe...
Runtime InvalidCastException with implicit cast operator
I have a C# library that internal clients configure with VB.Net Their scripts are throwing an InvalidCastException where they really shouldn't. So the code is something like this (massively simplified): //C#3 public class Foo { public static implicit operator Foo ( Bar input ) { return new Foo( input.Property1, input...
Which Json deserializer renders IList<T> collections?
I'm trying to deserialize json to an object model where the collections are represented as IList<T> types. The actual deserializing is here: JavaScriptSerializer serializer = new JavaScriptSerializer(); return serializer.Deserialize<IList<Contact>>( (new StreamReader(General.GetEmbeddedFile("Contacts.json")).ReadToEnd())); Befor...
Will the c# compiler perform multiple implicit conversions to get from one type to another?
Let's say you have yourself a class like the following: public sealed class StringToInt { private string _myString; private StringToInt(string value) { _myString = value; } public static implicit operator int(StringToInt obj) { return Convert.ToInt32(obj._myString); } public static im...
No implicit int -> short conversion in ternary statement
short s; s = (EitherTrueOrFalse()) ? 0 : 1; This fails with: error CS0266: Cannot implicitly convert type 'int' to 'short'. An explicit conversion exists (are you missing a cast?) Can anyone explain why this is so? The only thing I can think of is that the compiler doesn't look at the second value and doesn't know the range...
System.Type; implicit cast to string
Hello all, While looking at the System.Type class under the Code Definition Window, I cannot seem to understand how an instance of this class is implicitly cast to string. For example, on the following code: int foo = 0; Console.WriteLine("Hi! I'm a type of type {0}", foo.GetType()); How was the System.Type resulting from GetType() i...
C++ templates and ambiguity problem
I have a subset of a pointer class that look like: template <typename T> struct Pointer { Pointer(); Pointer(T *const x); Pointer(const Pointer &x); template <typename t> Pointer(const Pointer<t> &x); operator T *() const; }; The goal of the last constructor is to allow to pass a Pointer of a subclass, o...
Invaid cast exception, even when I have an implicit cast operator defined (in asp mvc app)
I have an mvc model class created and one of the properties is of type 'MyObject'. It also has a System.ComponentModel.DataAnnotations.StringLength attribute on it. MyObject as implicit cast operators so it can essentially be used as a string: public static implicit operator string(MyObject o){...} public static implicit operator MyOb...
Implicit version of IsAssignableFrom?
In my code using reflections i wrote if (f.FieldType.IsAssignableFrom("".GetType())) I have a class that has an implicit conversion to strings. However the if statement above doesnt catch it. How can i make reflection/the above if statement catch strings and classes with implicit string conversion? instead of specifically strings and ...
Is there a way to do dynamic implicit type casting in C#?
Given this class with an implicit cast operator: public class MyDateTime { public static implicit operator MyDateTime(System.Int64 encoded) { return new MyDateTime(encoded); } public MyDateTime(System.Int64 encoded) { _encoded = encoded; } System.Int64 _encoded; } I can now do the following...
Stopping an implicit cast on operator delete.
My String class provides an operator char* overload to allow you to pass the string to C functions. Unfortunately a colleague of mine just inadvertently discovered a bug. He effectively had the following code. StringT str; // Some code. delete str; Is there anyway to prevent delete from casting the string object to a char* to prev...
Implicit Conversion
My program was:- #include < iostream.h> #include < conio.h> struct base { protected: void get() { cin>>a>>b; } public: base(int i=0, int j=0); void put() { cout << a << '\t' << b << "\tput 1"; } int a,b,c; ~base() { cout << "base destroyed"; } }; class der...
Conditional operator cannot cast implicitly?
I'm a little stumped by this little C# quirk: Given variables: Boolean aBoolValue; Byte aByteValue; The following compiles: if (aBoolValue) aByteValue = 1; else aByteValue = 0; But this will not: aByteValue = aBoolValue ? 1 : 0; Error says: "Cannot implicitly convert type 'int' to 'byte'." And of course, this monstr...
C++, how implicit conversion/constructor are determined?
How does C++ determine implicit conversion/construction of objects few levels deep? for example: struct A {}; struct B: A {}; struct C { operator B() { return B(); } }; void f(A a) {} int main(void) { f(C()); } Does it create tree of all possible conversions and chooses appropriate terminal? Something else? Thanks ...
Implicit casting Integer calculation to float in C++
Is there any compiler that has a directive or a parameter to cast integer calculation to float implicitly. For example: float f = (1/3)*5; cout << f; the "f" is "0", because calculation's constants(1, 3, 10) are integer. I want to convert integer calculation with a compiler directive or parameter. I mean, I won't use explicit casting ...
How do i cast A to object to class A when B can typcast to A?
Basically i want to do this. aa causes a bad cast exception. NOTE: o can be ANYTHING. It may not be B, it can be C, D, E, F etc. But this should work as long as o is a class that can typecast into A (B is such a class. It uses an implicit operator overload) var b = (B)"sz"; var a = (A)b; object o = b; var...
Explanation of casting/conversion int/double in C#
I coded some calculation stuff (I copied below a really simplifed example of what I did) like CASE2 and got bad results. Refactored the code like CASE1 and worked fine. I know there is an implicit cast in CASE 2, but not sure of the full reason. Any one could explain me what´s exactly happening below? //CASE 1, result 5.5 double a...