diff --git a/Makefile.am b/Makefile.am index ca20ddf69..c73a1c141 100644 --- a/Makefile.am +++ b/Makefile.am @@ -511,6 +511,7 @@ libutil_a_SOURCES = \ src/util/FormatString.cxx src/util/FormatString.hxx \ src/util/Tokenizer.cxx src/util/Tokenizer.hxx \ src/util/TextFile.hxx \ + src/util/TemplateString.hxx \ src/util/TimeParser.cxx src/util/TimeParser.hxx \ src/util/UriUtil.cxx src/util/UriUtil.hxx \ src/util/Manual.hxx \ diff --git a/src/util/TemplateString.hxx b/src/util/TemplateString.hxx new file mode 100644 index 000000000..0d1329273 --- /dev/null +++ b/src/util/TemplateString.hxx @@ -0,0 +1,126 @@ +/* + * Copyright (C) 2015-2016 Max Kellermann + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef TEMPLATE_STRING_HXX +#define TEMPLATE_STRING_HXX + +#include + +namespace TemplateString { + /** + * Construct a null-terminated string from a list of chars. + */ + template + struct Construct { + static constexpr char value[] = {_value..., 0}; + static constexpr size_t size = sizeof...(_value); + }; + + template + constexpr char Construct<_value...>::value[]; + + /** + * An empty string. + */ + struct Empty : Construct<> {}; + + /** + * A string consisting of a single character. + */ + template + struct CharAsString : Construct {}; + + /** + * Invoke #F, pass all characters in #src from #i to #length + * as variadic arguments. + */ + template class F, + const char *src, size_t length, size_t i, + char... _value> + struct VariadicChars : VariadicChars { + static_assert(length > 0, "Wrong length"); + }; + + template class F, + const char *src, size_t length, + char... _value> + struct VariadicChars : F<_value...> {}; + + /** + * Like #VariadicChars, but pass an additional argument to #F. + */ + template class F, typename Arg, + const char *src, size_t length, size_t i, + char... _value> + struct VariadicChars1 : VariadicChars1 { + static_assert(length > 0, "Wrong length"); + }; + + template class F, typename Arg, + const char *src, size_t length, + char... _value> + struct VariadicChars1 : F {}; + + template + struct _BuildString : VariadicChars {}; + + template + struct InsertBefore : _BuildString {}; + + /** + * Concatenate several strings. + */ + template + struct Concat; + + template + struct _Concat : Concat, Args...> {}; + + template + struct Concat : _Concat {}; + + template + struct _Concat2 : _BuildString {}; + + template + struct Concat + :VariadicChars1<_Concat2, Second, + First::value, First::size, 0> {}; + + template + struct Concat : First {}; + + template<> + struct Concat<> : Empty {}; +}; + +#endif