Macros and constants are not remotely the same thing, each is sometimes appropriate for the circumstances, and your answer only scratches at the surface of the difference. Also, C++ has two different kinds of constants. A constant defined with the const qualifier is best thought of as an unmodifiable variable. It has all the properties … Read more
You are changing the pointer, which is not const (the thing it’s pointing to is const). If you want the pointer itself to be const, the declaration would look like: char * const str = “something”; or char const * const str = “something”; // a const pointer to const char const char * const … Read more
When both versions are available, the logic is pretty straightforward: const version is called for const objects, non-const version is called for non-const objects. That’s all. In your code sample a is a non-const object, meaning that the non-const version is called in all cases. The const version is never called in your sample. The … Read more
C and Python belongs to two different classes of languages. The former one is statically typed. The latter is dynamic. In a statically typed language, the type checker is able to infer the type of each expression and check if this match the given declaration during the “compilation” phase. In a dynamically typed language, the … Read more
The only way is to define() an expression and then use that constant in the class define(‘foobar’, ‘foo’ . ‘bar’); class Foo { const blah = foobar; } echo Foo::blah; Another option is to go to bugs.php.net and kindly ask them to fix this.
The const modifier is trivial: it modifies what precedes it, unless nothing precedes it. So: char const* buffer; // const modifies char char* const buffer; // const modifies * , etc. Generally, It’s best to avoid the forms where nothing precedes the const, but in practice, you’re going to see them, so you have to … Read more
You cannot do it with constants. The only possible way to do something that behaves like you want, but is not using constants, is to define a non-writable property: var obj = {}; Object.defineProperty( obj, “MY_FAKE_CONSTANT”, { value: “MY_FAKE_CONSTANT_VALUE”, writable: false, enumerable: true, configurable: true }); Regarding your question as to why a const passed … Read more
[The best answer was, unfortunately, deleted by a moderator because it was a link-only answer. I understand why link-only answers are discouraged; deleting it, however, has robbed future seekers of very useful information. The link has remained stable for more than seven years and continues to work at the time of this writing.] I strongly … Read more
Enum constants can only be of ordinal types (int by default), so you can’t have string constants in enums. When I want something like a “string-based enum” I create a class to hold the constants like you did, except I make it a static class to prevent both unwanted instantiation and unwanted subclassing. But if … Read more
The clearest answer. Does “X& const x” make any sense? No, it is nonsense To find out what the above declaration means, read it right-to-left: “x is a const reference to a X”. But that is redundant — references are always const, in the sense that you can never reseat a reference to make it … Read more