基本的な型
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(Also see the list of type-related utilities that are provided by C++.)
目次 |
[編集] Boolean 型
- bool - type, capable of holding one of the two values: true or false.
[編集] Character 型
- signed char - type for signed character representation.
- unsigned char - type for unsigned character representation.
- char - type for character representation which can be most efficiently processed on the target system (equivalent to either signed char or unsigned char).
- wchar_t - type for wide character representation
- char16_t - type for UTF-16 character representation (C++11およびそれ以降)
- char32_t - type for UTF-32 character representation (C++11およびそれ以降)
[編集] 整数型
- int - basic integer type. Can be omitted if any of the modifiers are present. If no length modifiers are present, guaranteed to have width of at least 16 bits. However, on 32/64 bit systems it is almost exclusively guaranteed to have width of at least 32 bits (see below).
[編集] 修飾子
Modifies the integer type. Can be mixed in any order. Only one of each group can be present in type definition.
Signedness
- signed - target type will have signed representation (this is the default if omitted)
- unsigned - target type will have unsigned representation
Size
- short - target type will be optimized for space and will have width of at least 16 bits.
- long - target type will have width of at least 32 bits.
- long long - target type will have width of at least 64 bits (C++11およびそれ以降)
[編集] 属性
The following table summarizes all available integer types and their properties:
| Type specifier | Equivalent type | Width in bits by data model | ||||
|---|---|---|---|---|---|---|
| C++ standard | LP32 | ILP32 | LLP64 | LP64 | ||
| short
|
short int | at least 16 |
16 | 16 | 16 | 16 |
| short int
| ||||||
| signed short
| ||||||
| signed short int
| ||||||
| unsigned short
|
unsigned short int | |||||
| unsigned short int
| ||||||
| int
|
int | at least 16 |
16 | 32 | 32 | 32 |
| signed
| ||||||
| signed int
| ||||||
| unsigned
|
unsigned int | |||||
| unsigned int
| ||||||
| long
|
long int | at least 32 |
32 | 32 | 32 | 64 |
| long int
| ||||||
| signed long
| ||||||
| signed long int
| ||||||
| unsigned long
|
unsigned long int | |||||
| unsigned long int
| ||||||
| long long
|
long long int (C++11) |
at least 64 |
64 | 64 | 64 | 64 |
| long long int
| ||||||
| signed long long
| ||||||
| signed long long int
| ||||||
| unsigned long long
|
unsigned long long int (C++11) | |||||
| unsigned long long int
| ||||||
Note: the C++ Standard guarantees that 1 == sizeof(char) <= sizeof(short) <= sizeof(int) <= sizeof(long) <= sizeof(long long).
[編集] データモデル
32ビットシステム:
- LP32:
- Win16 API
- ILP32;
- Win32 API
- Unix and Unix-like systems (Linux, Mac OS X)
64ビットシステム:
- LLP64
- Win64 API
- LP64
- Unix and Unix-like systems (Linux, Mac OS X)
[編集] 浮動小数点型
- float - 単精度浮動小数点型。通常は IEEE-754 32 ビット浮動小数点型である。
- double - 倍精度浮動小数点型。通常は IEEE-754 64 ビット浮動小数点型である。
- long double - extended precision floating point type. Does not necessarily map to types mandated by IEEE-754. Usually 80-bit x87 floating point type on x86 and x86-64 architectures.
[編集] 値の範囲
The following table provides a reference for limits of common numeric representations. Note, that all popular data models (including all of ILP32, LP32, LP64, LLP64) use two's complement arithmetic. Also, the C++ Standard does not specify which arithmetic would be used, thus it guarantees only the limits of one's complement arithmetic.
| Type | Size in bits | Format | Value range | |
|---|---|---|---|---|
| Approximate | Exact | |||
| character | 8 | signed (one's complement) | -127 to 127 | |
| signed (two's complement) | -128 to 127 | |||
| unsigned | 0 to 255 | |||
| integral | 16 | signed (one's complement) | ± 3.27 · 104 | -32767 to 32767 |
| signed (two's complement) | -32768 to 32767 | |||
| unsigned | 0 to 6.55 · 104 | 0 to 65535 | ||
| 32 | signed (one's complement) | ± 2.14 · 109 | -2,147,483,647 to 2,147,483,647 | |
| signed (two's complement) | -2,147,483,648 to 2,147,483,647 | |||
| unsigned | 0 to 4.29 · 109 | 0 to 4,294,967,295 | ||
| 64 | signed (one's complement) | ± 9.22 · 1018 | -9,223,372,036,854,775,807 to 9,223,372,036,854,775,807 | |
| signed (two's complement) | -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 | |||
| unsigned | 0 to 1.84 · 1019 | 0 to 18,446,744,073,709,551,615 | ||
| floating point |
32 | IEEE-754 | ± 3.4 · 10± 38 (~7 digits) |
|
| 64 | IEEE-754 | ± 1.7 · 10± 308 (~15 digits) |
| |
[編集] キーワード
bool, true, false, char, wchar_t, char16_t, char32_t, int, short, long, signed, unsigned, float, double
[編集] 参考
- <div class="t-tr-text"> CV指定</div>,Original:cv specifiersThe text has been machine-translated via [http://translate.google.com Google Translate].
You can help to correct and verify the translation. Click [http://en.cppreference.com/w/Cppreference:MachineTranslations here] for instructions. - <div class="t-tr-text"> 貯蔵期間指定</div>Original:storage duration specifiersThe text has been machine-translated via [http://translate.google.com Google Translate].
You can help to correct and verify the translation. Click [http://en.cppreference.com/w/Cppreference:MachineTranslations here] for instructions.
