rb_integer_unpack

rb_sys::bindings::uncategorized

Function rb_integer_unpack 

Source 
pub unsafe extern "C" fn rb_integer_unpack(
    words: *const c_void,
    numwords: size_t,
    wordsize: size_t,
    nails: size_t,
    flags: c_int,
) -> VALUE
Expand description

Import an integer from a buffer.

@param[in] words Buffer to import. @param[in] numwords Number of words of words. @param[in] wordsize Number of bytes per word. @param[in] nails Number of padding bits in a word. Most significant nails bits of each word are ignored. @param[in] flags Bitwise or of constants whose name starts “INTEGER_PACK_”. @exception rb_eArgError numwords * wordsize too big.

Possible flags are:

  • #INTEGER_PACK_MSWORD_FIRST: Interpret the first word as the most significant word.

  • #INTEGER_PACK_LSWORD_FIRST: Interpret the first word as the least significant word.

  • #INTEGER_PACK_MSBYTE_FIRST: Interpret the first byte in a word as the most significant byte in the word.

  • #INTEGER_PACK_LSBYTE_FIRST: Interpret the first byte in a word as the least significant byte in the word.

  • #INTEGER_PACK_NATIVE_BYTE_ORDER: Either #INTEGER_PACK_MSBYTE_FIRST or #INTEGER_PACK_LSBYTE_FIRST corresponding to the host’s endian.

  • #INTEGER_PACK_2COMP: Uses 2’s complement representation.

  • #INTEGER_PACK_LITTLE_ENDIAN: Shorthand of INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_LSBYTE_FIRST

  • #INTEGER_PACK_BIG_ENDIAN: Shorthand of INTEGER_PACK_MSWORD_FIRST|INTEGER_PACK_MSBYTE_FIRST

  • #INTEGER_PACK_FORCE_BIGNUM: Returns a bignum even if its value is representable as a fixnum.

  • #INTEGER_PACK_NEGATIVE: Returns a non-positive value. (Returns a non-negative value if not specified.)

  • #INTEGER_PACK_FORCE_GENERIC_IMPLEMENTATION: Uses generic implementation (for test and debug).

@return An instance of ::rb_cInteger whose value is the interpreted words. The range of the result value depends on #INTEGER_PACK_2COMP and #INTEGER_PACK_NEGATIVE.

When #INTEGER_PACK_2COMP is not set:

  • 0 <= val < 2**(numwords*(wordsize*CHAR_BIT-nails)) if !INTEGER_PACK_NEGATIVE

  • -2**(numwords*(wordsize*CHAR_BIT-nails)) < val <= 0 if INTEGER_PACK_NEGATIVE

When #INTEGER_PACK_2COMP is set:

  • -2**(numwords*(wordsize*CHAR_BIT-nails)-1) <= val <= 2**(numwords*(wordsize*CHAR_BIT-nails)-1)-1 if !INTEGER_PACK_NEGATIVE

  • -2**(numwords*(wordsize*CHAR_BIT-nails)) <= val <= -1 if INTEGER_PACK_NEGATIVE

Passing #INTEGER_PACK_2COMP without #INTEGER_PACK_NEGATIVE means sign extension. #INTEGER_PACK_2COMP with #INTEGER_PACK_NEGATIVE means assuming the higher bits are 1.

§Note that this function returns 0 when numwords is zero and #INTEGER_PACK_2COMP is set but #INTEGER_PACK_NEGATIVE is not set.

Generated by rb-sys for Ruby mri-x86_64-linux-gnu-3.2.3