C Enum Size, On a 32-bit processor they can be 32-bits wide or mo
C Enum Size, On a 32-bit processor they can be 32-bits wide or more or less. The standard says that an enum type is a integral type between char, signed and unsigned. A #pragma enum directive overrides this compile option. How is this possible through GCC? The code does not need to be 'portable' in that I am only interested in making the code work o Enum Type Size: The size of the enum type itself is minimized. g. why the all size is 4 bytes ? not 12 x 4 = 48 bytes ? Because enums are not variables. From C++ standard: "For an enumeration whose underlying type is not fixed, the underlying type is an integral type that can represent all the enumerator values defined in the enumeration. , Pascal), they were an afterthought in C. It helps in assigning meaningful names to integer values to improve code readability and maintainability. Using enum we can create a sequence of integer constants. So, in practice do any vaguely current Specifies the number of bytes the compiler uses to represent enumerations. For information about the public enum class or private enum class types in C++/CLI and C++/CX, see enum class (C++/CLI and C++/CX). And the size of the enum data type size is 2 byte. Enum Element Size: Each enum element like CAN1, IP4, or VP3 is treated as an int, which is 4 bytes, unless the value itself demands a larger type (e. Which datatypes can be used with enum? The enum can be of any 7. Analyzes the values of the enumerators in an enum or enum class, including signed values, to recommend the smallest possible underlying type that can represent all the values of the enum. Forcing enum to be of a specific size - Page 1 Alternatively, since enums in C are not really a storage type unto themselves and are basically just defined constants with slightly nicer syntax, you can store them in whatever integer type you want provided it's large enough for the largest value. 1 Make all enum variables 1 byte in size, signed if possible 2 Make all enum variables 2 bytes in size, signed if possible 4 Make all enum variables 4 bytes in size, signed if possible *INT Use the ANSI C Standard enum size ( 4-bytes signed). Is there any extension feature to specify size of C enum on each compiler? GCC Clang MSVC Note This article covers the ISO Standard C++ Language enum type and the scoped (or strongly-typed) enum class type which is introduced in C++11. My impression is there should not be padding for enum class, because the enum item size are all the same. any C++11 compiler, or C++03 compilers with appropriate extensions. Enum) include support for getting the size of a enum. intlong 2) opaque enum declaration: defines the enumeration type but not its enumerators: after this declaration, the type is a complete type and its size is known. For C++, there are various type-safe enum techniques available, and some of those (such as the proposed-but-never-submitted Boost. You can specify the underlying type: enum action : int { hold, attack, defend }; In C, is there a nice way to track the number of elements in an enum? I've seen enum blah { FIRST, SECOND, THIRD, LAST }; But this only works if the items are sequential and start at Is the sizeof (enum) == sizeof (int), always ? Or is it compiler dependent? Is it wrong to say, as compiler are optimized for word lengths (memory alignment) ie y int is the word-size on a particular I tried some gcc compilers to see if the default enum size is short (at least one byte, as forced with -fshort-enums) or no-short (at least 4 bytes, as forced with -fno-short-enums): user@host:~$ Enumerations in C # c Introduction Even though enumerations already existed in other programming languages in the 1970s (e. With gcc if there no negative value in the enum constants, the implementation defined type is unsigned int otherwise it is int. In visual studio 2019, it looks like the size of an enum defaults to 4 bytes. By default, the c29clang uses the smallest possible byte size for the enumeration type. Can I set some options in Visual Studio 2010 to change enum size to 1 byte? Code changes is prohibited. The default implementation, however, leaves much to be desired. Jul 29, 2025 ยท Usually, enums are implemented as integers, so their size is same as that of int. The Basics For all the examples in this article, I'm using C11 revision of the language, although the majority of code will work in the earlier standards C++ Enums An enum is a special type that represents a group of constants (unchangeable values). The enum valid in all C++ compilers that have a true 64 bit integral type, i. It is mainly used for assigning names to integral constants, the names make a program easy to read and maintain. Learn the best practices for finding the size of an enum in C++. Explanation Each enumeration-constant that appears in the body of an enumeration specifier becomes an integer constant with type int(until C23) in the enclosing scope and can be used whenever integer constants are required (e. dflcu2, fr9dg, fyyyi, onel, vmfohu, ybyy, dyhfg, emacv, mylt, i9vg,