#include <iostream> #include <vector> #include <algorithm> #include <iterator> #include <functional> #include <deque> using namespace std; #include <tr1/functional> using namespace std::tr1::placeholders; template<class Function_t> void for_each_x(Function_t func,int interval) { for(int sc = 0; sc < 10; sc+=interval){ func((con...
Outside of the ensuring that they cannot be changed (to the tune of a compiler error), does the JIT make any optimisations for const locals? Eg. public static int Main(string[] args) { const int timesToLoop = 50; for (int i=0; i<timesToLoop; i++) { // ... } } ...
I want to create a constant static array to be used throughout my Objective-C implementation file similar to something like this at the top level of my ".m" file: static const int NUM_TYPES = 4; static int types[NUM_TYPES] = { 1, 2, 3, 4 }; I plan on using NUM_TYPES later on in the file so I wanted to put it in a variable. ...
I was looking at this SO question and got to thinking about const ints versus #defines and realized I don't actually understand why the compiler can't deal with this. Could someone shed some light as to why the following code const int FOO = 10; int main(int argc, char** argv) { switch(argc) { case FOO: { printf("foo\n"...
Hello, I'm trying to initialize a private variable of my Class passing a const string &aString to it as parameter. Here's my method: void Image::initWithTextureFile(const std::string &inTextureName) { Texture2D *imTexture = TEXTURE_MANAGER->createTexture(inTextureName); if(imTexture) { texture = imTexture; sca...
I have a class member myMember that is a myType pointer. I want to assign this member in a function that is declared as const. I'm doing as follows: void func() const { ... const_cast<myType*>(myMember) = new myType(); ... } Doing this works fine in VC++, but GCC gives an error with the message "lvalue required as left ...
Hi, I am just learning C# and I have a problem now. :-) In C++ I loved to use "const reference" as a parameter to avoid that the called method changes my passed object. I read somewhere that I can do sth. similar in C# by using Interfaces. In the interface I would just put some "getters" to allow the method a readonly access to my obje...
I just found that when it comes to templates this code compiles in g++ 3.4.2 and works unless m() is not called: template <typename T> class C { T e; public: C(): e(0) {}; void m() { e = 0; }; }; Now one may create and use instance C<const int> c; Until c.m() is not called there are no compile errors b...
I have a problem in these lines: const int* index = faceArray[f].vertices; const Vector3& A = vertexArray[index[0]]; const Vector3& B = vertexArray[index[1]]; const Vector3& C = vertexArray[index[2]]; faceNormal[f] = Vector3::Cross(B - A, C - A).Normalize(); When I try to compile, I get an error: error C2678: binary '[' : no operat...
Hi! I'm a little confused as to why I've been told to return const foo from a binary operator in c++ instead of just foo. I've been reading Bruce Eckel's "Thinking in C++", and in the chapter on operator overloading, he says that "by making the return value [of an over-loading binary operator] const, you state that only a const member f...
Well, I think my problem originates in a lake of knowledge of basic C++ concepts. The problem is, in my code (below) I have the classes Header and Register. For both, I pass a reference to a ifstrem file already opened. The Header reads some bytes from it. Register has a method to return a reference of Header (which is passed in Register...
A similar question was previously asked, but none of the answers really provided what I was looking for. I am having trouble deciding where consts should be located in a function. I know a lot of people put them at the top, but if you put them as close as possible to where they are used, you'll reduce code span. I.e. void f() { const...
class School { static const int *classcapacity; }; This expression is from my exam and it need to get initialized how can i do that ? ...
I'm wondering if a class's member function should be const if it calls other functions that modify its data members. A good example would be a public member function that uses private member functions to do the brunt of the work. void Foo::Show() const { // Doesn't directly modify data members in this function ShowPig(); // One or a...
Say I have a function that takes a const reference to a pointer... Example: void Foo( const Bar *&p_Thing, ); and I pass a pointer Bar *blah = NULL; // Initialized when program starts up to the function Foo( blah ); I may encounter a compiler error like this invalid initialization of reference of type 'const Bar*&' from expres...
In C++ a stack-allocated object can be declared const: const Class object; after that trying to call a non-const method on such object is undefined behaviour: const_cast<Class*>( &object )->NonConstMethod(); //UB Can a heap-allocated object be const with the same consequences? I mean is it possible that the following: const Class*...
Given the following code: class foo; foo* instance = NULL; class foo { public: explicit foo(int j) : i(j) { instance = this; } void inc() { ++i; } private: int i; }; Is the following using defined behavior? const foo f(0); int main() { instance->inc(); } I'm asking because I'm using a cl...
class mystring { friend ostream& operator<<(ostream &out, const mystring ss) { out << ss.s; return out; } private: string s; public: mystring(const char ss[]) { cout << "constructing mystring : " << ss << endl; s = ss; } }; void outputStringByRef(const mystring &ss) { cout << "outputStri...
I met two explanation of const member function class A{ public: ... void f() const {} ... } it means it could only access constant members; it means it does not modify any members; I think the second one is right. But why does the first one come out? Is there anything to be clarify? Thanks! ...
DISCLAIMER: Please read carefully as this is NOT a question about storing arrays in constants or simple eval() or serialize() techniques. This IS a question primarily about how constants work in PHP and why the constant() function is not working to convert a constant name into a constant value. Thanks. BACKGROUND: For various reasons, I...