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Questions tagged [typedef]

In C and C++, the typedef keyword allows you to create an alias for a known data type.

The typedef keyword can be followed by any C and C++ built-in data type, including int, short, signed, unsigned, char, signed char, unsigned char, double, long, or long double. In C++, the data type can also be an existing class that either is provided by one of the libraries that ship with the C++ compiler. For example, it can be the string class. The data type can also be a pointer to a known type.

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What is a typedef enum in Objective-C?

I don't think I fundamentally understand what an enum is, and when to use it. For example: typedef enum { kCircle, kRectangle, kOblateSpheroid } ShapeType; What is really being declared here?
Craig
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What is the difference between 'typedef' and 'using' in C++11?

I know that in C++11 we can now use using to write type alias, like typedefs: typedef int MyInt; Is, from what I understand, equivalent to: using MyInt = int; And that new syntax emerged from the effort to have a way to express "template…
Klaim
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typedef struct vs struct definitions

I'm a beginner in C programming, but I was wondering what's the difference between using typedef when defining a structure versus not using typedef. It seems to me like there's really no difference, they accomplish the same goal. struct myStruct{ …
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Difference between 'struct' and 'typedef struct' in C++?

In C++, is there any difference between: struct Foo { ... }; and: typedef struct { ... } Foo;
criddell
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Typedef function pointer?

I'm learning how to dynamically load DLL's but what I don't understand is this line typedef void (*FunctionFunc)(); I have a few questions. If someone is able to answer them I would be grateful. Why is typedef used? The syntax looks odd; after…
Jack Harvin
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Why should we typedef a struct so often in C?

I have seen many programs consisting of structures like the one below typedef struct { int i; char k; } elem; elem user; Why is it needed so often? Any specific reason or applicable area?
Manoj Doubts
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C++ template typedef

I have a class template class Matrix { // .... }; I want to make a typedef which creates a Vector (column vector) which is equivalent to a Matrix with sizes N and 1. Something like that: typedef Matrix Vector; Which…
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Equivalent of typedef in C#

Is there a typedef equivalent in C#, or someway to get some sort of similar behaviour? I've done some googling, but everywhere I look seems to be negative. Currently I have a situation similar to the following: class GenericClass { public…
Matthew Scharley
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Is there a Java equivalent or methodology for the typedef keyword in C++?

Coming from a C and C++ background, I found judicious use of typedef to be incredibly helpful. Do you know of a way to achieve similar functionality in Java, whether that be a Java mechanism, pattern, or some other effective way you have used?
bn.
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Forward declaration of a typedef in C++

Why won't the compiler let me forward declare a typedef? Assuming it's impossible, what's the best practice for keeping my inclusion tree small?
user96825
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Understanding typedefs for function pointers in C

I have always been a bit stumped when I read other peoples' code which had typedefs for pointers to functions with arguments. I recall that it took me a while to get around to such a definition while trying to understand a numerical algorithm…
user192712
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uint8_t vs unsigned char

What is the advantage of using uint8_t over unsigned char in C? I know that on almost every system uint8_t is just a typedef for unsigned char, so why use it?
Lyndon White
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typedef fixed length array

I have to define a 24-bit data type.I am using char[3] to represent the type. Can I typedef char[3] to type24? I tried it in a code sample. I put typedef char[3] type24; in my header file. The compiler did not complain about it. But when I defined a…
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Why do you use typedef when declaring an enum in C++?

I haven't written any C++ in years and now I'm trying to get back into it. I then ran across this and thought about giving up: typedef enum TokenType { blah1 = 0x00000000, blah2 = 0X01000000, blah3 = 0X02000000 } TokenType; What…
Tim Merrifield
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How do I typedef a function pointer with the C++11 using syntax?

I'd like to write this typedef void (*FunctionPtr)(); using using. How would I do that?
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