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This article mainly introduces "C++11 how to specify the size of enum type", in daily operation, I believe many people have doubts on how to specify the size of enum type in C++11, Xiaobian consulted all kinds of information, sorted out simple and easy to use operation methods, hope to answer "C++11 how to specify the size of enum type" doubts helpful! Next, please follow the small series to learn together!

No Scope Specified

The size of an enumeration type automatically adjusts with the range of enumeration values. For example, the following code:

enumer_1 has only two enumeration values, and its size is 4 bytes; the first enumeration value of enumer_2 specifies a number over 32 bits, so the size is automatically adjusted to 8 bytes.

Scope specified

The default size for enumeration types is 4, which is the size of an int. For example, the following code:

The size of scope_enumer_1 can be output correctly, scope_enumer_2 directly raises a compilation error because it specifies a value exceeding 32 bits.

Specify the size of enum

The new C++11 standard allows enum type names followed by colons and types to specify the size of enumerated types. For example, we can specify the size of scope_enumer_2 as 8 bytes:

What's the point?

In short, of course, you can specify the size of the enumeration type. Of course, there is no convincing way to say this, so we will give a few examples:

When you want to save memory space

Enumerated values are exchanged between different operating systems, applications, or versions of applications (files or communications) to avoid incompatibility of data types.

Wait a minute.

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