Menu
very short question.
Is C++ typeof operator standard? de facto standard?
which compilers do not provided it (besides Microsoft C++)?
499
The typeof keyword is a new extension to the C language. The Oracle Developer Studio C compiler accepts constructs with typeof wherever a typedef name is accepted, including the following syntactic categories: Declarations. Parameter type lists and return types in a function declarator.
In other languages, such as C# or D and, to some degree, in C (as part of nonstandard extensions and proposed standard revisions), the typeof operator returns the static type of the operand. That is, it evaluates to the declared type at that instant in the program, irrespective of its original form.
The __typeof__ operator returns the type of its argument, which can be an expression or a type. The language feature provides a way to derive the type from an expression. Given an expression e , __typeof__(e) can be used anywhere a type name is needed, for example in a declaration or in a cast.
typeof is a JavaScript keyword that will return the type of a variable when you call it. You can use this to validate function parameters or check if variables are defined. There are other uses as well. The typeof operator is useful because it is an easy way to check the type of a variable in your code.
The typeof operator is nonstandard, but the upcoming C++ standard will have decltype.
88
As noted, C++0x has decltype. You can take a look at Boost.Typeof in the meantime.
45
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
