strideBack

uint strideBack(S)(auto  ref  S str,  size_t index) if (is(S :  const  char[])  ||
    (isRandomAccessRange!S &&  is(immutable  ElementType!S ==  immutable  char)))

Calculate the length of the UTF sequence ending one code unit before index in str.

Parameters

`str`	bidirectional range of UTF code units. Must be random access if `index` is passed
`index`	index one past end of UTF sequence (default: `str.length`)

Returns

The number of code units in the UTF sequence. For UTF-8, this is a

value between 1 and 4 (as per RFC 3629, section 3). For UTF-16, it is either 1 or 2. For UTF-32, it is always 1.

Throws

May throw a UTFException if str[index] is not one past the

end of a valid UTF sequence.

Note

strideBack will only analyze the element at str[index - 1]

element. It will not fully verify the validity of the UTF sequence, nor even verify the presence of the sequence: it will not actually guarantee that strideBack(str, index) <= index.

uint strideBack(S)(auto  ref  S str) if (is(S :  const  char[])  ||
    (isRandomAccessRange!S &&  hasLength!S &&  is(immutable  ElementType!S ==  immutable  char)))

Ditto

uint strideBack(S)(auto  ref  S str) if (isBidirectionalRange!S &&  is(immutable  ElementType!S ==  immutable  char)  && !isRandomAccessRange!S)

Ditto

uint strideBack(S)(auto  ref  S str,  size_t index) if (is(S :  const  wchar[])  ||
    (isRandomAccessRange!S &&  is(immutable  ElementType!S ==  immutable  wchar)))

Ditto

uint strideBack(S)(auto  ref  S str) if (is(S :  const  wchar[])  ||
    (isBidirectionalRange!S &&  is(immutable  ElementType!S ==  immutable  wchar)))

Ditto

uint strideBack(S)(auto  ref  S str,  size_t index) if (isRandomAccessRange!S &&  is(immutable  ElementEncodingType!S ==  immutable  dchar))

Ditto

uint strideBack(S)(auto  ref  S str) if (isBidirectionalRange!S &&  is(immutable  ElementEncodingType!S ==  immutable  dchar))

Ditto