Files
addr2line
ahash
aho_corasick
arrayref
arrayvec
artemis_asset
artemis_core
artemis_erc20_app
artemis_eth_app
artemis_ethereum
backtrace
base58
bip39
bitmask
bitvec
blake2_rfc
block_buffer
block_padding
byte_slice_cast
byte_tools
byteorder
cfg_if
clear_on_drop
const_random
const_random_macro
constant_time_eq
crunchy
crypto_mac
curve25519_dalek
derive_more
digest
ed25519_dalek
either
environmental
ethabi_decode
ethbloom
ethereum_types
failure
failure_derive
fake_simd
fixed_hash
frame_metadata
frame_support
frame_support_procedural
frame_support_procedural_tools
frame_support_procedural_tools_derive
frame_system
futures
futures_channel
futures_core
futures_executor
futures_io
futures_macro
futures_sink
futures_task
futures_util
async_await
future
io
lock
sink
stream
task
generic_array
getrandom
gimli
hash256_std_hasher
hash_db
hashbrown
hex
hex_literal
hmac
hmac_drbg
impl_codec
impl_rlp
impl_serde
impl_trait_for_tuples
inflector
cases
camelcase
case
classcase
kebabcase
pascalcase
screamingsnakecase
sentencecase
snakecase
tablecase
titlecase
traincase
numbers
deordinalize
ordinalize
string
constants
deconstantize
demodulize
pluralize
singularize
suffix
foreignkey
integer_sqrt
itertools
keccak
lazy_static
libc
lock_api
log
memchr
memory_db
memory_units
merlin
nodrop
num_bigint
num_cpus
num_integer
num_rational
num_traits
object
once_cell
opaque_debug
pallet_bridge
pallet_verifier
parity_scale_codec
parity_scale_codec_derive
parity_util_mem
parity_util_mem_derive
parity_wasm
parking_lot
parking_lot_core
paste
paste_impl
pbkdf2
pin_project
pin_project_internal
pin_utils
ppv_lite86
primitive_types
proc_macro2
proc_macro_crate
proc_macro_hack
proc_macro_nested
quote
radium
rand
rand_chacha
rand_core
rand_pcg
ref_cast
ref_cast_impl
regex
regex_syntax
rental
rental_impl
rlp
rustc_demangle
rustc_hash
rustc_hex
schnorrkel
scopeguard
secp256k1
serde
serde_derive
sha2
slab
smallvec
sp_application_crypto
sp_arithmetic
sp_core
sp_debug_derive
sp_externalities
sp_inherents
sp_io
sp_panic_handler
sp_runtime
sp_runtime_interface
sp_runtime_interface_proc_macro
sp_state_machine
sp_std
sp_storage
sp_tracing
sp_trie
sp_version
sp_wasm_interface
stable_deref_trait
static_assertions
substrate_bip39
subtle
syn
synstructure
thread_local
tiny_keccak
toml
tracing
tracing_attributes
tracing_core
trie_db
trie_root
twox_hash
typenum
uint
unicode_normalization
unicode_xid
wasmi
wasmi_validation
zeroize
zeroize_derive
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
// Copyright 2012-2016 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//
// Original authors: alexchrichton, bluss

// UTF-8 ranges and tags for encoding characters
const TAG_CONT: u8    = 0b1000_0000;
const TAG_TWO_B: u8   = 0b1100_0000;
const TAG_THREE_B: u8 = 0b1110_0000;
const TAG_FOUR_B: u8  = 0b1111_0000;
const MAX_ONE_B: u32   =     0x80;
const MAX_TWO_B: u32   =    0x800;
const MAX_THREE_B: u32 =  0x10000;

/// Placeholder
pub struct EncodeUtf8Error;

/// Encode a char into buf using UTF-8.
///
/// On success, return the byte length of the encoding (1, 2, 3 or 4).<br>
/// On error, return `EncodeUtf8Error` if the buffer was too short for the char.
#[inline]
pub fn encode_utf8(ch: char, buf: &mut [u8]) -> Result<usize, EncodeUtf8Error>
{
    let code = ch as u32;
    if code < MAX_ONE_B && buf.len() >= 1 {
        buf[0] = code as u8;
        return Ok(1);
    } else if code < MAX_TWO_B && buf.len() >= 2 {
        buf[0] = (code >> 6 & 0x1F) as u8 | TAG_TWO_B;
        buf[1] = (code & 0x3F) as u8 | TAG_CONT;
        return Ok(2);
    } else if code < MAX_THREE_B && buf.len() >= 3 {
        buf[0] = (code >> 12 & 0x0F) as u8 | TAG_THREE_B;
        buf[1] = (code >>  6 & 0x3F) as u8 | TAG_CONT;
        buf[2] = (code & 0x3F) as u8 | TAG_CONT;
        return Ok(3);
    } else if buf.len() >= 4 {
        buf[0] = (code >> 18 & 0x07) as u8 | TAG_FOUR_B;
        buf[1] = (code >> 12 & 0x3F) as u8 | TAG_CONT;
        buf[2] = (code >>  6 & 0x3F) as u8 | TAG_CONT;
        buf[3] = (code & 0x3F) as u8 | TAG_CONT;
        return Ok(4);
    };
    Err(EncodeUtf8Error)
}