777     bool isValidCodeUnit(E c) @safe pure @nogc nothrow  in GenericEncoder()
870     bool isValidCodeUnit(AsciiChar c) @safe pure nothrow @nogc  in isValidCodeUnit()  function
953     bool isValidCodeUnit(Latin1Char c) @safe pure nothrow @nogc  in isValidCodeUnit()  function
1338     bool isValidCodeUnit(char c) @safe pure nothrow @nogc  in isValidCodeUnit()  function
1504     bool isValidCodeUnit(wchar c) @safe pure nothrow @nogc  in isValidCodeUnit()  function
1601     bool isValidCodeUnit(dchar c) @safe pure @nogc nothrow  in isValidCodeUnit()  function
1760 bool isValidCodeUnit(E)(E c)  in isValidCodeUnit()  function
1762     return EncoderInstance!(E).isValidCodeUnit(c);  in isValidCodeUnit()
1768     assert(!isValidCodeUnit(cast(char) 0xC0));
1769     assert(!isValidCodeUnit(cast(char) 0xFF));
1770     assert( isValidCodeUnit(cast(wchar) 0xD800));
1771     assert(!isValidCodeUnit(cast(dchar) 0xD800));
1772     assert(!isValidCodeUnit(cast(AsciiChar) 0xA0));
1773     assert( isValidCodeUnit(cast(Windows1250Char) 0x80));
1774     assert(!isValidCodeUnit(cast(Windows1250Char) 0x81));
1775     assert( isValidCodeUnit(cast(Windows1251Char) 0x80));
1776     assert(!isValidCodeUnit(cast(Windows1251Char) 0x98));
1777     assert( isValidCodeUnit(cast(Windows1252Char) 0x80));
1778     assert(!isValidCodeUnit(cast(Windows1252Char) 0x81));