core.internal.utf

pure nothrow @nogc @safe bool isValidDchar(dchar c);

Test if c is a valid UTF-32 character.

\uFFFE and \uFFFF are considered valid by this function, as they are permitted for internal use by an application, but they are not allowed for interchange by the Unicode standard.

Returns:

true if it is, false if not.

pure nothrow @nogc @safe uint stride(scope const char[] s, size_t i);

stride() returns the length of a UTF-8 sequence starting at index i in string s.

Returns:

The number of bytes in the UTF-8 sequence or 0xFF meaning s[i] is not the start of of UTF-8 sequence.

pure nothrow @nogc @safe uint stride(scope const wchar[] s, size_t i);

stride() returns the length of a UTF-16 sequence starting at index i in string s.

pure nothrow @nogc @safe uint stride(scope const dchar[] s, size_t i);

stride() returns the length of a UTF-32 sequence starting at index i in string s.

Returns:

The return value will always be 1.

pure @safe size_t toUCSindex(scope const char[] s, size_t i);

pure @safe size_t toUCSindex(scope const wchar[] s, size_t i);

pure nothrow @nogc @safe size_t toUCSindex(scope const dchar[] s, size_t i);

Given an index i into an array of characters s[], and assuming that index i is at the start of a UTF character, determine the number of UCS characters up to that index i.

pure @safe size_t toUTFindex(scope const char[] s, size_t n);

pure nothrow @nogc @safe size_t toUTFindex(scope const wchar[] s, size_t n);

pure nothrow @nogc @safe size_t toUTFindex(scope const dchar[] s, size_t n);

Given a UCS index n into an array of characters s[], return the UTF index.

pure @safe dchar decode(scope const char[] s, ref size_t idx);

pure @safe dchar decode(scope const wchar[] s, ref size_t idx);

pure @safe dchar decode(scope const dchar[] s, ref size_t idx);

Decodes and returns character starting at s[idx]. idx is advanced past the decoded character. If the character is not well formed, a UtfException is thrown and idx remains unchanged.

pure nothrow @safe void encode(ref char[] s, dchar c);

pure nothrow @safe void encode(ref wchar[] s, dchar c);

pure nothrow @safe void encode(ref dchar[] s, dchar c);

Encodes character c and appends it to array s[].

pure nothrow @nogc @safe ubyte codeLength(C)(dchar c);

Returns the code length of c in the encoding using C as a code point. The code is returned in character count, not in bytes.

pure nothrow @safe bool isValidString(S)(scope const S s);

Checks to see if string is well formed or not. S can be an array of char, wchar, or dchar. Returns false if it is not. Use to check all untrusted input for correctness.

pure nothrow @safe string toUTF8(return scope string s);

pure @trusted string toUTF8(scope const wchar[] s);

pure @trusted string toUTF8(scope const dchar[] s);

Encodes string s into UTF-8 and returns the encoded string.

pure @trusted wstring toUTF16(scope const char[] s);

pure @safe wptr toUTF16z(scope const char[] s);

pure nothrow @safe wstring toUTF16(return scope wstring s);

pure nothrow @trusted wstring toUTF16(scope const dchar[] s);

Encodes string s into UTF-16 and returns the encoded string. toUTF16z() is suitable for calling the 'W' functions in the Win32 API that take an LPWSTR or LPCWSTR argument.

pure @trusted dstring toUTF32(scope const char[] s);

pure @trusted dstring toUTF32(scope const wchar[] s);

pure nothrow @safe dstring toUTF32(return scope dstring s);

Encodes string s into UTF-32 and returns the encoded string.