The simplest fix is to make the comparator function be static: static int comparator (const Bar & first, const Bar & second); ^^^^^^ When invoking it in Count, its name will be Foo::comparator. The way you have it now, it does not make sense to be a non-static member function because it does not use … Read more
That’s fine and is the typical way of doing it. You will have to declare expensive_object_ as mutable mutable QObject *expensive_object_; mutable basically means “I know I’m in a const object, but modifying this won’t break const-ness.”
const is a proposed feature of ECMAScript Harmony (together with a properly block-scoped let it is supposed to replace var and implicit globals). ECMAScript Harmony is a grab-bag of ideas for the next versions of ECMAScript. const was also a part of ECMAScript 4. ECMAScript 4 was never released and never will be, and ECMAScript … Read more
GCC: pure/const function attributes llvm-gcc: supports the GCC pure/const attributes Clang: seems to support it (I tried on a simple example with the GCC style attributes and it worked.) ICC: seems to adopt the GCC attributes (Sorry, only a forum post.) MSVC: Seems not to support it. (discussion) In general, it seems that almost all … Read more
A way to design your way around this, if needed, is to use two different types for the same object: one read/write type and one read-only type. typedef struct { char *ptrChar; } A_rw; typedef struct { const char* ptrChar; } A_ro; typedef union { A_rw rw; A_ro ro; } A; If a function needs … Read more
Your class is a POD (essentially because it doesn’t provide a default constructor). POD variables are not initialized upon declaration. That is, this: foo x; does not initialize x to a meaningful value. This has to be done separately. Now, when you declare it as const, this may never happen because you cannot assign to … Read more
C# uses 0x and VB.NET uses &H as the prefix to specify hexadecimal numbers. try this. Public Const temp As Integer = &HE6359A60 Sub Main End Sub And it could be as Uint also: Public Const temp As UInt32 = &HE6359A60UI Sub Main End Sub Check MSDN’s Type Characters (Visual Basic) documentation for defining hexadecimal … Read more
If you have a class of configuration values, like your Constants class, and you want to load all values from a configuration (properties) file, you can create a little helper class and use reflection: public class ConfigLoader { public static void load(Class<?> configClass, String file) { try { Properties props = new Properties(); try (FileInputStream … Read more
There are a couple of things that affect the answer: First, as long as the value is const it will almost certainly be optimized out in any case. That means that the resulting code will most likely be the same. Second, static members are stored elsewhere which means less locality and probably a cache miss. … Read more
The key thing to remember is that const and “constant” mean two quite different things. The const keyword really means “read-only”. A constant is a numeric literal, such as 42 or 1.5 (or an enumeration or character constant). A constant expression is a particular kind of expression that can be evaluated at compile time, such … Read more