<QtTypes> - Qt Type Declarations

详细描述

The header file declares several type definitions that guarantee a specified bit-size on all platforms supported by Qt for various basic types, for example qint8 which is a signed char guaranteed to be 8-bit on all platforms supported by Qt. The header file also declares the qlonglong type definition for long long int .

Several convenience type definitions are declared: qreal for double or float , uchar for unsigned char , uint for 无符号 int , ulong for unsigned long and ushort for unsigned short .

The header also provides series of macros that make it possible to print some Qt type aliases (qsizetype, qintptr, etc.) via a formatted output facility such as printf() or qDebug () without raising formatting warnings and without the need of a type cast.

类型文档编制

qint8

Typedef 为 signed char 。此类型保证在 Qt 支持的所有平台为 8 位。

qint16

Typedef 为 signed short 。此类型保证在 Qt 支持的所有平台为 16 位。

qint32

Typedef 为 signed int 。此类型保证在 Qt 支持的所有平台为 32 位。

qint64

Typedef 为 long long int . This type is guaranteed to be 64-bit on all platforms supported by Qt.

可以创建此类型的文字使用 Q_INT64_C () 宏：

qint64 value = Q_INT64_C(932838457459459);
					

另请参阅 Q_INT64_C (), quint64 ，和 qlonglong .

[since 6.6] qint128

Typedef 为 __int128 on platforms that support it (Qt defines the macro QT_SUPPORTS_INT128 if this is the case).

可以创建此类型的文字使用 Q_INT128_C () 宏。

This typedef was introduced in Qt 6.6.

另请参阅 Q_INT128_C (), Q_INT128_MIN , Q_INT128_MAX , quint128 ，和 QT_SUPPORTS_INT128 .

qintptr

用于以有符号整数表示指针的整型 (对哈希等有用)。

typedef 为 qint32 或 qint64。此类型保证在 Qt 支持的所有平台，指针的大小相同。在采用 32 位指针的系统中，qintptr typedef 为 qint32；在采用 64 位指针的系统中，qintptr typedef 为 qint64。

注意，qintptr 有符号。使用 quintptr 对于无符号值。

In order to print values of this type by using formatted-output facilities such as printf() , qDebug (), QString::asprintf () and so on, you can use the PRIdQINTPTR and PRIiQINTPTR macros as format specifiers. They will both print the value as a base 10 number.

qintptr p = 123;
printf("The pointer is %" PRIdQINTPTR "\n", p);
					

另请参阅 qptrdiff , qint32 ，和 qint64 .

qlonglong

Typedef 为 long long int ( __int64 在 Windows)。这如同 qint64 .

另请参阅 qulonglong and qint64 .

qptrdiff

用于表示指针差异的整型。

Typedef for either qint32 or qint64. This type is guaranteed to be the same size as a pointer on all platforms supported by Qt. On a system with 32-bit pointers, quintptr is a typedef for quint32; on a system with 64-bit pointers, quintptr is a typedef for quint64.

注意：qptrdiff 是有符号的。使用 quintptr 为无符号值。

In order to print values of this type by using formatted-output facilities such as printf() , qDebug (), QString::asprintf () and so on, you can use the PRIdQPTRDIFF and PRIiQPTRDIFF macros as format specifiers. They will both print the value as a base 10 number.

qptrdiff d = 123;
printf("The difference is %" PRIdQPTRDIFF "\n", d);
					

另请参阅 quintptr , qint32 ，和 qint64 .

qreal

Typedef 为 double 除非配置 Qt 采用 -qreal float 选项。

[alias] qsizetype

整型类型提供 POSIX ssize_t 对于所有平台。

此类型保证相同大小如 size_t 在 Qt 支持的所有平台。

注意：qsizetype 无符号。使用 size_t 对于无符号值。

In order to print values of this type by using formatted-output facilities such as printf() , qDebug (), QString::asprintf () and so on, you can use the PRIdQSIZETYPE and PRIiQSIZETYPE macros as format specifiers. They will both print the value as a base 10 number.

qsizetype s = 123;
printf("The size is %" PRIdQSIZETYPE "\n", s);
					

另请参阅 qptrdiff .

quint8

Typedef 为 unsigned char 。此类型保证在 Qt 支持的所有平台为 8 位。

quint16

Typedef 为 unsigned short 。此类型保证在 Qt 支持的所有平台为 16 位。

quint32

Typedef 为 无符号 int 。此类型保证在 Qt 支持的所有平台为 32 位。

quint64

Typedef 为 unsigned long long int . This type is guaranteed to be 64-bit on all platforms supported by Qt.

可以创建此类型的文字使用 Q_UINT64_C () 宏：

quint64 value = Q_UINT64_C(932838457459459);
					

另请参阅 Q_UINT64_C (), qint64 ，和 qulonglong .

[since 6.6] quint128

Typedef 为 unsigned __int128 on platforms that support it (Qt defines the macro QT_SUPPORTS_INT128 if this is the case).

可以创建此类型的文字使用 Q_UINT128_C () 宏。

This typedef was introduced in Qt 6.6.

另请参阅 Q_UINT128_C (), Q_UINT128_MAX , qint128 ，和 QT_SUPPORTS_INT128 .

quintptr

Integral type for representing pointers in an unsigned integer (useful for hashing, etc.).

Typedef for either quint32 or quint64. This type is guaranteed to be the same size as a pointer on all platforms supported by Qt. On a system with 32-bit pointers, quintptr is a typedef for quint32; on a system with 64-bit pointers, quintptr is a typedef for quint64.

Note that quintptr is unsigned. Use qptrdiff for signed values.

In order to print values of this type by using formatted-output facilities such as printf() , qDebug (), QString::asprintf () and so on, you can use the following macros as format specifiers:

• PRIuQUINTPTR : prints the value as a base 10 number.
• PRIoQUINTPTR : prints the value as a base 8 number.
• PRIxQUINTPTR : prints the value as a base 16 number, using lowercase a-f letters.
• PRIXQUINTPTR : prints the value as a base 16 number, using uppercase A-F letters.

quintptr p = 123u;
printf("The pointer value is 0x%" PRIXQUINTPTR "\n", p);
					

另请参阅 qptrdiff , quint32 ，和 quint64 .

qulonglong

Typedef 为 unsigned long long int ( unsigned __int64 在 Windows)。这如同 quint64 .

另请参阅 quint64 and qlonglong .

uchar

方便 typedef 为 unsigned char .

uint

方便 typedef 为 无符号 int .

ulong

方便 typedef 为 unsigned long .

ushort

方便 typedef 为 unsigned short .

宏文档编制

[since 6.2] PRIdQINTPTR

[since 6.2] PRIiQINTPTR

见 qintptr .

该函数在 Qt 6.2 引入。

[since 6.2] PRIXQUINTPTR

[since 6.2] PRIoQUINTPTR

[since 6.2] PRIuQUINTPTR

[since 6.2] PRIxQUINTPTR

See quintptr.

该函数在 Qt 6.2 引入。

[since 6.2] PRIdQPTRDIFF

[since 6.2] PRIiQPTRDIFF

See qptrdiff.

该函数在 Qt 6.2 引入。

[since 6.2] PRIdQSIZETYPE

[since 6.2] PRIiQSIZETYPE

See qsizetype.

该函数在 Qt 6.2 引入。

[since 6.2] PRIXQUINTPTR

This macro was introduced in Qt 6.2.

[since 6.2] PRIdQINTPTR

This macro was introduced in Qt 6.2.

[since 6.2] PRIdQPTRDIFF

This macro was introduced in Qt 6.2.

[since 6.2] PRIdQSIZETYPE

This macro was introduced in Qt 6.2.

[since 6.2] PRIiQINTPTR

This macro was introduced in Qt 6.2.

[since 6.2] PRIiQPTRDIFF

This macro was introduced in Qt 6.2.

[since 6.2] PRIiQSIZETYPE

This macro was introduced in Qt 6.2.

[since 6.2] PRIoQUINTPTR

This macro was introduced in Qt 6.2.

[since 6.2] PRIuQUINTPTR

This macro was introduced in Qt 6.2.

[since 6.2] PRIxQUINTPTR

This macro was introduced in Qt 6.2.

[since 6.6] QT_SUPPORTS_INT128

Qt defines this macro as well as the qint128 and quint128 types if the platform has support for 128-bit integer types.

This macro was introduced in Qt 6.6.

另请参阅 qint128 , quint128 , Q_INT128_C (), Q_UINT128_C (), Q_INT128_MIN , Q_INT128_MAX ，和 Q_UINT128_MAX .

[since 6.6] qint128 Q_INT128_C ( literal )

Wraps the signed 128-bit integer literal in a platform-independent way.

注意： 不像 Q_INT64_C (), this macro is only available in C++, not in C. This is because compilers do not provide these literals as built-ins and C does not have support for user-defined literals.

This macro was introduced in Qt 6.6.

另请参阅 qint128 , Q_UINT128_C (), Q_INT128_MIN , Q_INT128_MAX , Q_INT64_C ()，和 QT_SUPPORTS_INT128 .

[since 6.6] Q_INT128_MAX

This macro expands to a compile-time constant representing the maximum value representable in a qint128 .

This macro is available in both C++ and C modes.

This macro was introduced in Qt 6.6.

另请参阅 Q_INT128_MIN , Q_UINT128_MAX , qint128 , Q_INT128_C ，和 QT_SUPPORTS_INT128 .

[since 6.6] Q_INT128_MIN

This macro expands to a compile-time constant representing the minimum value representable in a qint128 .

This macro is available in both C++ and C modes.

This macro was introduced in Qt 6.6.

另请参阅 Q_INT128_MAX , qint128 , Q_INT128_C ，和 QT_SUPPORTS_INT128 .

qint64 Q_INT64_C ( literal )

Wraps the signed 64-bit integer literal in a platform-independent way.

范例：

qint64 value = Q_INT64_C(932838457459459);
					

另请参阅 qint64 , Q_UINT64_C ()，和 Q_INT128_C ().

[since 6.6] quint128 Q_UINT128_C ( literal )

Wraps the unsigned 128-bit integer literal in a platform-independent way.

注意： 不像 Q_UINT64_C (), this macro is only available in C++, not in C. This is because compilers do not provide these literals as built-ins and C does not have support for user-defined literals.

This macro was introduced in Qt 6.6.

另请参阅 quint128 , Q_INT128_C (), Q_UINT128_MAX , Q_UINT64_C ()，和 QT_SUPPORTS_INT128 .

[since 6.6] Q_UINT128_MAX

This macro expands to a compile-time constant representing the maximum value representable in a quint128 .

This macro is available in both C++ and C modes.

The minimum of quint128 is 0 (zero), so a Q_UINT128_MIN is neither needed nor provided.

This macro was introduced in Qt 6.6.

另请参阅 Q_INT128_MAX , quint128 , Q_UINT128_C ，和 QT_SUPPORTS_INT128 .

quint64 Q_UINT64_C ( literal )

Wraps the unsigned 64-bit integer literal in a platform-independent way.

范例：

quint64 value = Q_UINT64_C(932838457459459);
					

另请参阅 quint64 , Q_INT64_C ()，和 Q_UINT128_C ().