| // Formatting library for C++ - experimental range support |
| // |
| // Copyright (c) 2012 - present, Victor Zverovich |
| // All rights reserved. |
| // |
| // For the license information refer to format.h. |
| // |
| // Copyright (c) 2018 - present, Remotion (Igor Schulz) |
| // All Rights Reserved |
| // {fmt} support for ranges, containers and types tuple interface. |
| |
| #ifndef FMT_RANGES_H_ |
| #define FMT_RANGES_H_ |
| |
| #include <initializer_list> |
| #include <type_traits> |
| |
| #include "format.h" |
| |
| // output only up to N items from the range. |
| #ifndef FMT_RANGE_OUTPUT_LENGTH_LIMIT |
| # define FMT_RANGE_OUTPUT_LENGTH_LIMIT 256 |
| #endif |
| |
| FMT_BEGIN_NAMESPACE |
| |
| template <typename Char> struct formatting_base { |
| template <typename ParseContext> |
| FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) { |
| return ctx.begin(); |
| } |
| }; |
| |
| template <typename Char, typename Enable = void> |
| struct formatting_range : formatting_base<Char> { |
| static FMT_CONSTEXPR_DECL const size_t range_length_limit = |
| FMT_RANGE_OUTPUT_LENGTH_LIMIT; // output only up to N items from the |
| // range. |
| Char prefix; |
| Char delimiter; |
| Char postfix; |
| formatting_range() : prefix('{'), delimiter(','), postfix('}') {} |
| static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true; |
| static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false; |
| }; |
| |
| template <typename Char, typename Enable = void> |
| struct formatting_tuple : formatting_base<Char> { |
| Char prefix; |
| Char delimiter; |
| Char postfix; |
| formatting_tuple() : prefix('('), delimiter(','), postfix(')') {} |
| static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true; |
| static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false; |
| }; |
| |
| namespace detail { |
| |
| template <typename RangeT, typename OutputIterator> |
| OutputIterator copy(const RangeT& range, OutputIterator out) { |
| for (auto it = range.begin(), end = range.end(); it != end; ++it) |
| *out++ = *it; |
| return out; |
| } |
| |
| template <typename OutputIterator> |
| OutputIterator copy(const char* str, OutputIterator out) { |
| while (*str) *out++ = *str++; |
| return out; |
| } |
| |
| template <typename OutputIterator> |
| OutputIterator copy(char ch, OutputIterator out) { |
| *out++ = ch; |
| return out; |
| } |
| |
| /// Return true value if T has std::string interface, like std::string_view. |
| template <typename T> class is_like_std_string { |
| template <typename U> |
| static auto check(U* p) |
| -> decltype((void)p->find('a'), p->length(), (void)p->data(), int()); |
| template <typename> static void check(...); |
| |
| public: |
| static FMT_CONSTEXPR_DECL const bool value = |
| is_string<T>::value || !std::is_void<decltype(check<T>(nullptr))>::value; |
| }; |
| |
| template <typename Char> |
| struct is_like_std_string<fmt::basic_string_view<Char>> : std::true_type {}; |
| |
| template <typename... Ts> struct conditional_helper {}; |
| |
| template <typename T, typename _ = void> struct is_range_ : std::false_type {}; |
| |
| #if !FMT_MSC_VER || FMT_MSC_VER > 1800 |
| template <typename T> |
| struct is_range_< |
| T, conditional_t<false, |
| conditional_helper<decltype(std::declval<T>().begin()), |
| decltype(std::declval<T>().end())>, |
| void>> : std::true_type {}; |
| #endif |
| |
| /// tuple_size and tuple_element check. |
| template <typename T> class is_tuple_like_ { |
| template <typename U> |
| static auto check(U* p) -> decltype(std::tuple_size<U>::value, int()); |
| template <typename> static void check(...); |
| |
| public: |
| static FMT_CONSTEXPR_DECL const bool value = |
| !std::is_void<decltype(check<T>(nullptr))>::value; |
| }; |
| |
| // Check for integer_sequence |
| #if defined(__cpp_lib_integer_sequence) || FMT_MSC_VER >= 1900 |
| template <typename T, T... N> |
| using integer_sequence = std::integer_sequence<T, N...>; |
| template <size_t... N> using index_sequence = std::index_sequence<N...>; |
| template <size_t N> using make_index_sequence = std::make_index_sequence<N>; |
| #else |
| template <typename T, T... N> struct integer_sequence { |
| using value_type = T; |
| |
| static FMT_CONSTEXPR size_t size() { return sizeof...(N); } |
| }; |
| |
| template <size_t... N> using index_sequence = integer_sequence<size_t, N...>; |
| |
| template <typename T, size_t N, T... Ns> |
| struct make_integer_sequence : make_integer_sequence<T, N - 1, N - 1, Ns...> {}; |
| template <typename T, T... Ns> |
| struct make_integer_sequence<T, 0, Ns...> : integer_sequence<T, Ns...> {}; |
| |
| template <size_t N> |
| using make_index_sequence = make_integer_sequence<size_t, N>; |
| #endif |
| |
| template <class Tuple, class F, size_t... Is> |
| void for_each(index_sequence<Is...>, Tuple&& tup, F&& f) FMT_NOEXCEPT { |
| using std::get; |
| // using free function get<I>(T) now. |
| const int _[] = {0, ((void)f(get<Is>(tup)), 0)...}; |
| (void)_; // blocks warnings |
| } |
| |
| template <class T> |
| FMT_CONSTEXPR make_index_sequence<std::tuple_size<T>::value> get_indexes( |
| T const&) { |
| return {}; |
| } |
| |
| template <class Tuple, class F> void for_each(Tuple&& tup, F&& f) { |
| const auto indexes = get_indexes(tup); |
| for_each(indexes, std::forward<Tuple>(tup), std::forward<F>(f)); |
| } |
| |
| template <typename Range> |
| using value_type = remove_cvref_t<decltype(*std::declval<Range>().begin())>; |
| |
| template <typename Arg, FMT_ENABLE_IF(!is_like_std_string< |
| typename std::decay<Arg>::type>::value)> |
| FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const Arg&) { |
| return add_space ? " {}" : "{}"; |
| } |
| |
| template <typename Arg, FMT_ENABLE_IF(is_like_std_string< |
| typename std::decay<Arg>::type>::value)> |
| FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const Arg&) { |
| return add_space ? " \"{}\"" : "\"{}\""; |
| } |
| |
| FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const char*) { |
| return add_space ? " \"{}\"" : "\"{}\""; |
| } |
| FMT_CONSTEXPR const wchar_t* format_str_quoted(bool add_space, const wchar_t*) { |
| return add_space ? L" \"{}\"" : L"\"{}\""; |
| } |
| |
| FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const char) { |
| return add_space ? " '{}'" : "'{}'"; |
| } |
| FMT_CONSTEXPR const wchar_t* format_str_quoted(bool add_space, const wchar_t) { |
| return add_space ? L" '{}'" : L"'{}'"; |
| } |
| } // namespace detail |
| |
| template <typename T> struct is_tuple_like { |
| static FMT_CONSTEXPR_DECL const bool value = |
| detail::is_tuple_like_<T>::value && !detail::is_range_<T>::value; |
| }; |
| |
| template <typename TupleT, typename Char> |
| struct formatter<TupleT, Char, enable_if_t<fmt::is_tuple_like<TupleT>::value>> { |
| private: |
| // C++11 generic lambda for format() |
| template <typename FormatContext> struct format_each { |
| template <typename T> void operator()(const T& v) { |
| if (i > 0) { |
| if (formatting.add_prepostfix_space) { |
| *out++ = ' '; |
| } |
| out = detail::copy(formatting.delimiter, out); |
| } |
| out = format_to(out, |
| detail::format_str_quoted( |
| (formatting.add_delimiter_spaces && i > 0), v), |
| v); |
| ++i; |
| } |
| |
| formatting_tuple<Char>& formatting; |
| size_t& i; |
| typename std::add_lvalue_reference<decltype( |
| std::declval<FormatContext>().out())>::type out; |
| }; |
| |
| public: |
| formatting_tuple<Char> formatting; |
| |
| template <typename ParseContext> |
| FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) { |
| return formatting.parse(ctx); |
| } |
| |
| template <typename FormatContext = format_context> |
| auto format(const TupleT& values, FormatContext& ctx) -> decltype(ctx.out()) { |
| auto out = ctx.out(); |
| size_t i = 0; |
| detail::copy(formatting.prefix, out); |
| |
| detail::for_each(values, format_each<FormatContext>{formatting, i, out}); |
| if (formatting.add_prepostfix_space) { |
| *out++ = ' '; |
| } |
| detail::copy(formatting.postfix, out); |
| |
| return ctx.out(); |
| } |
| }; |
| |
| template <typename T, typename Char> struct is_range { |
| static FMT_CONSTEXPR_DECL const bool value = |
| detail::is_range_<T>::value && !detail::is_like_std_string<T>::value && |
| !std::is_convertible<T, std::basic_string<Char>>::value && |
| !std::is_constructible<detail::std_string_view<Char>, T>::value; |
| }; |
| |
| template <typename T, typename Char> |
| struct formatter< |
| T, Char, |
| enable_if_t<fmt::is_range<T, Char>::value |
| // Workaround a bug in MSVC 2017 and earlier. |
| #if !FMT_MSC_VER || FMT_MSC_VER >= 1927 |
| && |
| (has_formatter<detail::value_type<T>, format_context>::value || |
| detail::has_fallback_formatter<detail::value_type<T>, |
| format_context>::value) |
| #endif |
| >> { |
| formatting_range<Char> formatting; |
| |
| template <typename ParseContext> |
| FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) { |
| return formatting.parse(ctx); |
| } |
| |
| template <typename FormatContext> |
| typename FormatContext::iterator format(const T& values, FormatContext& ctx) { |
| auto out = detail::copy(formatting.prefix, ctx.out()); |
| size_t i = 0; |
| auto it = values.begin(); |
| auto end = values.end(); |
| for (; it != end; ++it) { |
| if (i > 0) { |
| if (formatting.add_prepostfix_space) *out++ = ' '; |
| out = detail::copy(formatting.delimiter, out); |
| } |
| out = format_to(out, |
| detail::format_str_quoted( |
| (formatting.add_delimiter_spaces && i > 0), *it), |
| *it); |
| if (++i > formatting.range_length_limit) { |
| out = format_to(out, " ... <other elements>"); |
| break; |
| } |
| } |
| if (formatting.add_prepostfix_space) *out++ = ' '; |
| return detail::copy(formatting.postfix, out); |
| } |
| }; |
| |
| template <typename Char, typename... T> struct tuple_arg_join : detail::view { |
| const std::tuple<T...>& tuple; |
| basic_string_view<Char> sep; |
| |
| tuple_arg_join(const std::tuple<T...>& t, basic_string_view<Char> s) |
| : tuple{t}, sep{s} {} |
| }; |
| |
| template <typename Char, typename... T> |
| struct formatter<tuple_arg_join<Char, T...>, Char> { |
| template <typename ParseContext> |
| FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) { |
| return ctx.begin(); |
| } |
| |
| template <typename FormatContext> |
| typename FormatContext::iterator format( |
| const tuple_arg_join<Char, T...>& value, FormatContext& ctx) { |
| return format(value, ctx, detail::make_index_sequence<sizeof...(T)>{}); |
| } |
| |
| private: |
| template <typename FormatContext, size_t... N> |
| typename FormatContext::iterator format( |
| const tuple_arg_join<Char, T...>& value, FormatContext& ctx, |
| detail::index_sequence<N...>) { |
| return format_args(value, ctx, std::get<N>(value.tuple)...); |
| } |
| |
| template <typename FormatContext> |
| typename FormatContext::iterator format_args( |
| const tuple_arg_join<Char, T...>&, FormatContext& ctx) { |
| // NOTE: for compilers that support C++17, this empty function instantiation |
| // can be replaced with a constexpr branch in the variadic overload. |
| return ctx.out(); |
| } |
| |
| template <typename FormatContext, typename Arg, typename... Args> |
| typename FormatContext::iterator format_args( |
| const tuple_arg_join<Char, T...>& value, FormatContext& ctx, |
| const Arg& arg, const Args&... args) { |
| using base = formatter<typename std::decay<Arg>::type, Char>; |
| auto out = ctx.out(); |
| out = base{}.format(arg, ctx); |
| if (sizeof...(Args) > 0) { |
| out = std::copy(value.sep.begin(), value.sep.end(), out); |
| ctx.advance_to(out); |
| return format_args(value, ctx, args...); |
| } |
| return out; |
| } |
| }; |
| |
| /** |
| \rst |
| Returns an object that formats `tuple` with elements separated by `sep`. |
| |
| **Example**:: |
| |
| std::tuple<int, char> t = {1, 'a'}; |
| fmt::print("{}", fmt::join(t, ", ")); |
| // Output: "1, a" |
| \endrst |
| */ |
| template <typename... T> |
| FMT_CONSTEXPR tuple_arg_join<char, T...> join(const std::tuple<T...>& tuple, |
| string_view sep) { |
| return {tuple, sep}; |
| } |
| |
| template <typename... T> |
| FMT_CONSTEXPR tuple_arg_join<wchar_t, T...> join(const std::tuple<T...>& tuple, |
| wstring_view sep) { |
| return {tuple, sep}; |
| } |
| |
| /** |
| \rst |
| Returns an object that formats `initializer_list` with elements separated by |
| `sep`. |
| |
| **Example**:: |
| |
| fmt::print("{}", fmt::join({1, 2, 3}, ", ")); |
| // Output: "1, 2, 3" |
| \endrst |
| */ |
| template <typename T> |
| arg_join<const T*, const T*, char> join(std::initializer_list<T> list, |
| string_view sep) { |
| return join(std::begin(list), std::end(list), sep); |
| } |
| |
| template <typename T> |
| arg_join<const T*, const T*, wchar_t> join(std::initializer_list<T> list, |
| wstring_view sep) { |
| return join(std::begin(list), std::end(list), sep); |
| } |
| |
| FMT_END_NAMESPACE |
| |
| #endif // FMT_RANGES_H_ |