- Endian Conversion Functions | Qt Core (original) (raw)

The header provides functions to convert between little and big endian representations of numbers. More...

Function Documentation

template T qFromBigEndian(const void *src)

Reads a big-endian number from memory location src and returns the number in the host byte order representation. On CPU architectures where the host byte order is little-endian (such as x86) this will swap the byte order; otherwise it will just read from src.

Note: Template type T can either be a quint16, qint16, quint32, qint32, quint64, or qint64. Other types of integers, e.g., qlong, are not applicable.

Note: Since Qt 5.7, the type of the src parameter is a void pointer.

There are no data alignment constraints for src.

See also qFromLittleEndian(), qToBigEndian(), and qToLittleEndian().

[constexpr] template T qFromBigEndian(T src)

This is an overloaded function.

Converts src from big-endian byte order and returns the number in host byte order representation of that number. On CPU architectures where the host byte order is little-endian (such as x86) this will return src with the byte order swapped; otherwise it will return src unmodified.

template void qFromBigEndian(const void *src, qsizetype count, void *dest)

Reads count big-endian numbers from memory location src and stores them in the host byte order representation at dest. On CPU architectures where the host byte order is little-endian (such as x86) this will swap the byte order; otherwise it will just perform a memcpy from src to dest.

Note: Template type T can either be a quint16, qint16, quint32, qint32, quint64, or qint64. Other types of integers, e.g., qlong, are not applicable.

There are no data alignment constraints for src. However, dest is expected to be naturally aligned for type T.

If src and dest can be the same pointer, this function will perform an in-place swap (if necessary). If they are not the same, the memory regions must not overlap.

See also qFromLittleEndian(), qToBigEndian(), and qToLittleEndian().

template T qFromLittleEndian(const void *src)

Reads a little-endian number from memory location src and returns the number in the host byte order representation. On CPU architectures where the host byte order is big-endian (such as PowerPC) this will swap the byte order; otherwise it will just read from src.

Note: Template type T can either be a quint16, qint16, quint32, qint32, quint64, or qint64. Other types of integers, e.g., qlong, are not applicable.

Note: Since Qt 5.7, the type of the src parameter is a void pointer.

There are no data alignment constraints for src.

See also qFromBigEndian(), qToBigEndian(), and qToLittleEndian().

[constexpr] template T qFromLittleEndian(T src)

This is an overloaded function.

Converts src from little-endian byte order and returns the number in host byte order representation of that number. On CPU architectures where the host byte order is big-endian (such as PowerPC) this will return src with the byte order swapped; otherwise it will return src unmodified.

template void qFromLittleEndian(const void *src, qsizetype count, void *dest)

Reads count little-endian numbers from memory location src and stores them in the host byte order representation at dest. On CPU architectures where the host byte order is big-endian (such as PowerPC) this will swap the byte order; otherwise it will just perform a memcpy from src to dest.

Note: Template type T can either be a quint16, qint16, quint32, qint32, quint64, or qint64. Other types of integers, e.g., qlong, are not applicable.

There are no data alignment constraints for src. However, dest is expected to be naturally aligned for type T.

If src and dest can be the same pointer, this function will perform an in-place swap (if necessary). If they are not the same, the memory regions must not overlap.

See also qToBigEndian() and qToLittleEndian().

template void qToBigEndian(T src, void *dest)

Writes the number src with template type T to the memory location at dest in big-endian byte order.

Note: Template type T can either be a quint16, qint16, quint32, qint32, quint64, or qint64. Other types of integers, e.g., qlong, are not applicable.

There are no data alignment constraints for dest.

Note: Since Qt 5.7, the type of the dest parameter is a void pointer.

See also qFromBigEndian(), qFromLittleEndian(), and qToLittleEndian().

[constexpr] template T qToBigEndian(T src)

This is an overloaded function.

Converts src from host byte order and returns the number in big-endian byte order representation of that number. On CPU architectures where the host byte order is little-endian (such as x86) this will return src with the byte order swapped; otherwise it will return src unmodified.

template void qToBigEndian(const void *src, qsizetype count, void *dest)

Reads count numbers from memory location src in the host byte order and stores them in big-endian representation at dest. On CPU architectures where the host byte order is little-endian (such as x86) this will swap the byte order; otherwise it will just perform a memcpy from src to dest.

Note: Template type T can either be a quint16, qint16, quint32, qint32, quint64, or qint64. Other types of integers, e.g., qlong, are not applicable.

There are no data alignment constraints for dest. However, src is expected to be naturally aligned for type T.

If src and dest can be the same pointer, this function will perform an in-place swap (if necessary). If they are not the same, the memory regions must not overlap.

See also qFromLittleEndian(), qToBigEndian(), and qToLittleEndian().

template void qToLittleEndian(T src, void *dest)

Writes the number src with template type T to the memory location at dest in little-endian byte order.

Note: Template type T can either be a quint16, qint16, quint32, qint32, quint64, or qint64. Other types of integers, e.g., qlong, are not applicable.

There are no data alignment constraints for dest.

Note: Since Qt 5.7, the type of the dest parameter is a void pointer.

See also qFromBigEndian(), qFromLittleEndian(), and qToBigEndian().

[constexpr] template T qToLittleEndian(T src)

This is an overloaded function.

Converts src from host byte order and returns the number in little-endian byte order representation of that number. On CPU architectures where the host byte order is big-endian (such as PowerPC) this will return src with the byte order swapped; otherwise it will return src unmodified.

template void qToLittleEndian(const void *src, qsizetype count, void *dest)

Reads count numbers from memory location src in the host byte order and stores them in little-endian representation at dest. On CPU architectures where the host byte order is big-endian (such as PowerPC) this will swap the byte order; otherwise it will just perform a memcpy from src to dest.

Note: Template type T can either be a quint16, qint16, quint32, qint32, quint64, or qint64. Other types of integers, e.g., qlong, are not applicable.

There are no data alignment constraints for dest. However, src is expected to be naturally aligned for type T.

If src and dest can be the same pointer, this function will perform an in-place swap (if necessary). If they are not the same, the memory regions must not overlap.

See also qFromLittleEndian(), qToBigEndian(), and qToLittleEndian().