codepoint_width_4

vstd::utf8

Function codepoint_width_4 

Source 
pub open spec fn codepoint_width_4(byte1: u8, byte2: u8, byte3: u8, byte4: u8) -> u32
Expand description
recommends
is_leading_byte_width_4(byte1),
is_continuation_byte(byte2),
is_continuation_byte(byte3),
is_continuation_byte(byte4),
{
    (leading_bits_width_4(byte1) << 18) | (continuation_bits(byte2) << 12)
        | (continuation_bits(byte3) << 6) | continuation_bits(byte4)
}

The codepoint encoded by the given 4 bytes, assuming that they are a valid leading and continuation bytes, respectively, for 4-byte UTF-8 encoding.