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ranges.h
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ranges.h
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// 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 <tuple>
#include <type_traits>
#include "format.h"
FMT_BEGIN_NAMESPACE
namespace detail {
template <typename Range, typename OutputIt>
auto copy(const Range& range, OutputIt out) -> OutputIt {
for (auto it = range.begin(), end = range.end(); it != end; ++it)
*out++ = *it;
return out;
}
template <typename OutputIt>
auto copy(const char* str, OutputIt out) -> OutputIt {
while (*str) *out++ = *str++;
return out;
}
template <typename OutputIt> auto copy(char ch, OutputIt out) -> OutputIt {
*out++ = ch;
return out;
}
template <typename OutputIt> auto copy(wchar_t ch, OutputIt out) -> OutputIt {
*out++ = ch;
return out;
}
// Returns true if T has a std::string-like interface, like std::string_view.
template <typename T> class is_std_string_like {
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 constexpr const bool value =
is_string<T>::value ||
std::is_convertible<T, std_string_view<char>>::value ||
!std::is_void<decltype(check<T>(nullptr))>::value;
};
template <typename Char>
struct is_std_string_like<fmt::basic_string_view<Char>> : std::true_type {};
template <typename T> class is_map {
template <typename U> static auto check(U*) -> typename U::mapped_type;
template <typename> static void check(...);
public:
#ifdef FMT_FORMAT_MAP_AS_LIST // DEPRECATED!
static constexpr const bool value = false;
#else
static constexpr const bool value =
!std::is_void<decltype(check<T>(nullptr))>::value;
#endif
};
template <typename T> class is_set {
template <typename U> static auto check(U*) -> typename U::key_type;
template <typename> static void check(...);
public:
#ifdef FMT_FORMAT_SET_AS_LIST // DEPRECATED!
static constexpr const bool value = false;
#else
static constexpr const bool value =
!std::is_void<decltype(check<T>(nullptr))>::value && !is_map<T>::value;
#endif
};
template <typename... Ts> struct conditional_helper {};
template <typename T, typename _ = void> struct is_range_ : std::false_type {};
#if !FMT_MSC_VERSION || FMT_MSC_VERSION > 1800
# define FMT_DECLTYPE_RETURN(val) \
->decltype(val) { return val; } \
static_assert( \
true, "") // This makes it so that a semicolon is required after the
// macro, which helps clang-format handle the formatting.
// C array overload
template <typename T, std::size_t N>
auto range_begin(const T (&arr)[N]) -> const T* {
return arr;
}
template <typename T, std::size_t N>
auto range_end(const T (&arr)[N]) -> const T* {
return arr + N;
}
template <typename T, typename Enable = void>
struct has_member_fn_begin_end_t : std::false_type {};
template <typename T>
struct has_member_fn_begin_end_t<T, void_t<decltype(std::declval<T>().begin()),
decltype(std::declval<T>().end())>>
: std::true_type {};
// Member function overload
template <typename T>
auto range_begin(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).begin());
template <typename T>
auto range_end(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).end());
// ADL overload. Only participates in overload resolution if member functions
// are not found.
template <typename T>
auto range_begin(T&& rng)
-> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
decltype(begin(static_cast<T&&>(rng)))> {
return begin(static_cast<T&&>(rng));
}
template <typename T>
auto range_end(T&& rng) -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
decltype(end(static_cast<T&&>(rng)))> {
return end(static_cast<T&&>(rng));
}
template <typename T, typename Enable = void>
struct has_const_begin_end : std::false_type {};
template <typename T, typename Enable = void>
struct has_mutable_begin_end : std::false_type {};
template <typename T>
struct has_const_begin_end<
T,
void_t<
decltype(detail::range_begin(std::declval<const remove_cvref_t<T>&>())),
decltype(detail::range_end(std::declval<const remove_cvref_t<T>&>()))>>
: std::true_type {};
template <typename T>
struct has_mutable_begin_end<
T, void_t<decltype(detail::range_begin(std::declval<T>())),
decltype(detail::range_end(std::declval<T>())),
// the extra int here is because older versions of MSVC don't
// SFINAE properly unless there are distinct types
int>> : std::true_type {};
template <typename T>
struct is_range_<T, void>
: std::integral_constant<bool, (has_const_begin_end<T>::value ||
has_mutable_begin_end<T>::value)> {};
# undef FMT_DECLTYPE_RETURN
#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 constexpr const bool value =
!std::is_void<decltype(check<T>(nullptr))>::value;
};
// Check for integer_sequence
#if defined(__cpp_lib_integer_sequence) || FMT_MSC_VERSION >= 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 <typename T>
using tuple_index_sequence = make_index_sequence<std::tuple_size<T>::value>;
template <typename T, typename C, bool = is_tuple_like_<T>::value>
class is_tuple_formattable_ {
public:
static constexpr const bool value = false;
};
template <typename T, typename C> class is_tuple_formattable_<T, C, true> {
template <std::size_t... Is>
static std::true_type check2(index_sequence<Is...>,
integer_sequence<bool, (Is == Is)...>);
static std::false_type check2(...);
template <std::size_t... Is>
static decltype(check2(
index_sequence<Is...>{},
integer_sequence<
bool, (is_formattable<typename std::tuple_element<Is, T>::type,
C>::value)...>{})) check(index_sequence<Is...>);
public:
static constexpr const bool value =
decltype(check(tuple_index_sequence<T>{}))::value;
};
template <typename Tuple, typename F, size_t... Is>
FMT_CONSTEXPR void for_each(index_sequence<Is...>, Tuple&& t, F&& f) {
using std::get;
// Using a free function get<Is>(Tuple) now.
const int unused[] = {0, ((void)f(get<Is>(t)), 0)...};
ignore_unused(unused);
}
template <typename Tuple, typename F>
FMT_CONSTEXPR void for_each(Tuple&& t, F&& f) {
for_each(tuple_index_sequence<remove_cvref_t<Tuple>>(),
std::forward<Tuple>(t), std::forward<F>(f));
}
template <typename Tuple1, typename Tuple2, typename F, size_t... Is>
void for_each2(index_sequence<Is...>, Tuple1&& t1, Tuple2&& t2, F&& f) {
using std::get;
const int unused[] = {0, ((void)f(get<Is>(t1), get<Is>(t2)), 0)...};
ignore_unused(unused);
}
template <typename Tuple1, typename Tuple2, typename F>
void for_each2(Tuple1&& t1, Tuple2&& t2, F&& f) {
for_each2(tuple_index_sequence<remove_cvref_t<Tuple1>>(),
std::forward<Tuple1>(t1), std::forward<Tuple2>(t2),
std::forward<F>(f));
}
namespace tuple {
// Workaround a bug in MSVC 2019 (v140).
template <typename Char, typename... T>
using result_t = std::tuple<formatter<remove_cvref_t<T>, Char>...>;
using std::get;
template <typename Tuple, typename Char, std::size_t... Is>
auto get_formatters(index_sequence<Is...>)
-> result_t<Char, decltype(get<Is>(std::declval<Tuple>()))...>;
} // namespace tuple
#if FMT_MSC_VERSION && FMT_MSC_VERSION < 1920
// Older MSVC doesn't get the reference type correctly for arrays.
template <typename R> struct range_reference_type_impl {
using type = decltype(*detail::range_begin(std::declval<R&>()));
};
template <typename T, std::size_t N> struct range_reference_type_impl<T[N]> {
using type = T&;
};
template <typename T>
using range_reference_type = typename range_reference_type_impl<T>::type;
#else
template <typename Range>
using range_reference_type =
decltype(*detail::range_begin(std::declval<Range&>()));
#endif
// We don't use the Range's value_type for anything, but we do need the Range's
// reference type, with cv-ref stripped.
template <typename Range>
using uncvref_type = remove_cvref_t<range_reference_type<Range>>;
template <typename Formatter>
FMT_CONSTEXPR auto maybe_set_debug_format(Formatter& f, bool set)
-> decltype(f.set_debug_format(set)) {
f.set_debug_format(set);
}
template <typename Formatter>
FMT_CONSTEXPR void maybe_set_debug_format(Formatter&, ...) {}
// These are not generic lambdas for compatibility with C++11.
template <typename ParseContext> struct parse_empty_specs {
template <typename Formatter> FMT_CONSTEXPR void operator()(Formatter& f) {
f.parse(ctx);
detail::maybe_set_debug_format(f, true);
}
ParseContext& ctx;
};
template <typename FormatContext> struct format_tuple_element {
using char_type = typename FormatContext::char_type;
template <typename T>
void operator()(const formatter<T, char_type>& f, const T& v) {
if (i > 0)
ctx.advance_to(detail::copy_str<char_type>(separator, ctx.out()));
ctx.advance_to(f.format(v, ctx));
++i;
}
int i;
FormatContext& ctx;
basic_string_view<char_type> separator;
};
} // namespace detail
template <typename T> struct is_tuple_like {
static constexpr const bool value =
detail::is_tuple_like_<T>::value && !detail::is_range_<T>::value;
};
template <typename T, typename C> struct is_tuple_formattable {
static constexpr const bool value =
detail::is_tuple_formattable_<T, C>::value;
};
template <typename Tuple, typename Char>
struct formatter<Tuple, Char,
enable_if_t<fmt::is_tuple_like<Tuple>::value &&
fmt::is_tuple_formattable<Tuple, Char>::value>> {
private:
decltype(detail::tuple::get_formatters<Tuple, Char>(
detail::tuple_index_sequence<Tuple>())) formatters_;
basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
basic_string_view<Char> opening_bracket_ =
detail::string_literal<Char, '('>{};
basic_string_view<Char> closing_bracket_ =
detail::string_literal<Char, ')'>{};
public:
FMT_CONSTEXPR formatter() {}
FMT_CONSTEXPR void set_separator(basic_string_view<Char> sep) {
separator_ = sep;
}
FMT_CONSTEXPR void set_brackets(basic_string_view<Char> open,
basic_string_view<Char> close) {
opening_bracket_ = open;
closing_bracket_ = close;
}
template <typename ParseContext>
FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
auto it = ctx.begin();
if (it != ctx.end() && *it != '}')
FMT_THROW(format_error("invalid format specifier"));
detail::for_each(formatters_, detail::parse_empty_specs<ParseContext>{ctx});
return it;
}
template <typename FormatContext>
auto format(const Tuple& value, FormatContext& ctx) const
-> decltype(ctx.out()) {
ctx.advance_to(detail::copy_str<Char>(opening_bracket_, ctx.out()));
detail::for_each2(
formatters_, value,
detail::format_tuple_element<FormatContext>{0, ctx, separator_});
return detail::copy_str<Char>(closing_bracket_, ctx.out());
}
};
template <typename T, typename Char> struct is_range {
static constexpr const bool value =
detail::is_range_<T>::value && !detail::is_std_string_like<T>::value &&
!std::is_convertible<T, std::basic_string<Char>>::value &&
!std::is_convertible<T, detail::std_string_view<Char>>::value;
};
namespace detail {
template <typename Context> struct range_mapper {
using mapper = arg_mapper<Context>;
template <typename T,
FMT_ENABLE_IF(has_formatter<remove_cvref_t<T>, Context>::value)>
static auto map(T&& value) -> T&& {
return static_cast<T&&>(value);
}
template <typename T,
FMT_ENABLE_IF(!has_formatter<remove_cvref_t<T>, Context>::value)>
static auto map(T&& value)
-> decltype(mapper().map(static_cast<T&&>(value))) {
return mapper().map(static_cast<T&&>(value));
}
};
template <typename Char, typename Element>
using range_formatter_type =
formatter<remove_cvref_t<decltype(range_mapper<buffer_context<Char>>{}.map(
std::declval<Element>()))>,
Char>;
template <typename R>
using maybe_const_range =
conditional_t<has_const_begin_end<R>::value, const R, R>;
// Workaround a bug in MSVC 2015 and earlier.
#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
template <typename R, typename Char>
struct is_formattable_delayed
: is_formattable<uncvref_type<maybe_const_range<R>>, Char> {};
#endif
} // namespace detail
template <typename T, typename Char, typename Enable = void>
struct range_formatter;
template <typename T, typename Char>
struct range_formatter<
T, Char,
enable_if_t<conjunction<std::is_same<T, remove_cvref_t<T>>,
is_formattable<T, Char>>::value>> {
private:
detail::range_formatter_type<Char, T> underlying_;
basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
basic_string_view<Char> opening_bracket_ =
detail::string_literal<Char, '['>{};
basic_string_view<Char> closing_bracket_ =
detail::string_literal<Char, ']'>{};
public:
FMT_CONSTEXPR range_formatter() {}
FMT_CONSTEXPR auto underlying() -> detail::range_formatter_type<Char, T>& {
return underlying_;
}
FMT_CONSTEXPR void set_separator(basic_string_view<Char> sep) {
separator_ = sep;
}
FMT_CONSTEXPR void set_brackets(basic_string_view<Char> open,
basic_string_view<Char> close) {
opening_bracket_ = open;
closing_bracket_ = close;
}
template <typename ParseContext>
FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
auto it = ctx.begin();
auto end = ctx.end();
if (it != end && *it == 'n') {
set_brackets({}, {});
++it;
}
if (it != end && *it != '}') {
if (*it != ':') FMT_THROW(format_error("invalid format specifier"));
++it;
} else {
detail::maybe_set_debug_format(underlying_, true);
}
ctx.advance_to(it);
return underlying_.parse(ctx);
}
template <typename R, typename FormatContext>
auto format(R&& range, FormatContext& ctx) const -> decltype(ctx.out()) {
detail::range_mapper<buffer_context<Char>> mapper;
auto out = ctx.out();
out = detail::copy_str<Char>(opening_bracket_, out);
int i = 0;
auto it = detail::range_begin(range);
auto end = detail::range_end(range);
for (; it != end; ++it) {
if (i > 0) out = detail::copy_str<Char>(separator_, out);
ctx.advance_to(out);
out = underlying_.format(mapper.map(*it), ctx);
++i;
}
out = detail::copy_str<Char>(closing_bracket_, out);
return out;
}
};
enum class range_format { disabled, map, set, sequence, string, debug_string };
namespace detail {
template <typename T>
struct range_format_kind_
: std::integral_constant<range_format,
std::is_same<uncvref_type<T>, T>::value
? range_format::disabled
: is_map<T>::value ? range_format::map
: is_set<T>::value ? range_format::set
: range_format::sequence> {};
template <range_format K, typename R, typename Char, typename Enable = void>
struct range_default_formatter;
template <range_format K>
using range_format_constant = std::integral_constant<range_format, K>;
template <range_format K, typename R, typename Char>
struct range_default_formatter<
K, R, Char,
enable_if_t<(K == range_format::sequence || K == range_format::map ||
K == range_format::set)>> {
using range_type = detail::maybe_const_range<R>;
range_formatter<detail::uncvref_type<range_type>, Char> underlying_;
FMT_CONSTEXPR range_default_formatter() { init(range_format_constant<K>()); }
FMT_CONSTEXPR void init(range_format_constant<range_format::set>) {
underlying_.set_brackets(detail::string_literal<Char, '{'>{},
detail::string_literal<Char, '}'>{});
}
FMT_CONSTEXPR void init(range_format_constant<range_format::map>) {
underlying_.set_brackets(detail::string_literal<Char, '{'>{},
detail::string_literal<Char, '}'>{});
underlying_.underlying().set_brackets({}, {});
underlying_.underlying().set_separator(
detail::string_literal<Char, ':', ' '>{});
}
FMT_CONSTEXPR void init(range_format_constant<range_format::sequence>) {}
template <typename ParseContext>
FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
return underlying_.parse(ctx);
}
template <typename FormatContext>
auto format(range_type& range, FormatContext& ctx) const
-> decltype(ctx.out()) {
return underlying_.format(range, ctx);
}
};
} // namespace detail
template <typename T, typename Char, typename Enable = void>
struct range_format_kind
: conditional_t<
is_range<T, Char>::value, detail::range_format_kind_<T>,
std::integral_constant<range_format, range_format::disabled>> {};
template <typename R, typename Char>
struct formatter<
R, Char,
enable_if_t<conjunction<bool_constant<range_format_kind<R, Char>::value !=
range_format::disabled>
// Workaround a bug in MSVC 2015 and earlier.
#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
,
detail::is_formattable_delayed<R, Char>
#endif
>::value>>
: detail::range_default_formatter<range_format_kind<R, Char>::value, R,
Char> {
};
template <typename Char, typename... T> struct tuple_join_view : detail::view {
const std::tuple<T...>& tuple;
basic_string_view<Char> sep;
tuple_join_view(const std::tuple<T...>& t, basic_string_view<Char> s)
: tuple(t), sep{s} {}
};
// Define FMT_TUPLE_JOIN_SPECIFIERS to enable experimental format specifiers
// support in tuple_join. It is disabled by default because of issues with
// the dynamic width and precision.
#ifndef FMT_TUPLE_JOIN_SPECIFIERS
# define FMT_TUPLE_JOIN_SPECIFIERS 0
#endif
template <typename Char, typename... T>
struct formatter<tuple_join_view<Char, T...>, Char> {
template <typename ParseContext>
FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
return do_parse(ctx, std::integral_constant<size_t, sizeof...(T)>());
}
template <typename FormatContext>
auto format(const tuple_join_view<Char, T...>& value,
FormatContext& ctx) const -> typename FormatContext::iterator {
return do_format(value, ctx,
std::integral_constant<size_t, sizeof...(T)>());
}
private:
std::tuple<formatter<typename std::decay<T>::type, Char>...> formatters_;
template <typename ParseContext>
FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
std::integral_constant<size_t, 0>)
-> decltype(ctx.begin()) {
return ctx.begin();
}
template <typename ParseContext, size_t N>
FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
std::integral_constant<size_t, N>)
-> decltype(ctx.begin()) {
auto end = ctx.begin();
#if FMT_TUPLE_JOIN_SPECIFIERS
end = std::get<sizeof...(T) - N>(formatters_).parse(ctx);
if (N > 1) {
auto end1 = do_parse(ctx, std::integral_constant<size_t, N - 1>());
if (end != end1)
FMT_THROW(format_error("incompatible format specs for tuple elements"));
}
#endif
return end;
}
template <typename FormatContext>
auto do_format(const tuple_join_view<Char, T...>&, FormatContext& ctx,
std::integral_constant<size_t, 0>) const ->
typename FormatContext::iterator {
return ctx.out();
}
template <typename FormatContext, size_t N>
auto do_format(const tuple_join_view<Char, T...>& value, FormatContext& ctx,
std::integral_constant<size_t, N>) const ->
typename FormatContext::iterator {
auto out = std::get<sizeof...(T) - N>(formatters_)
.format(std::get<sizeof...(T) - N>(value.tuple), ctx);
if (N > 1) {
out = std::copy(value.sep.begin(), value.sep.end(), out);
ctx.advance_to(out);
return do_format(value, ctx, std::integral_constant<size_t, N - 1>());
}
return out;
}
};
namespace detail {
// Check if T has an interface like a container adaptor (e.g. std::stack,
// std::queue, std::priority_queue).
template <typename T> class is_container_adaptor_like {
template <typename U> static auto check(U* p) -> typename U::container_type;
template <typename> static void check(...);
public:
static constexpr const bool value =
!std::is_void<decltype(check<T>(nullptr))>::value;
};
template <typename Container> struct all {
const Container& c;
auto begin() const -> typename Container::const_iterator { return c.begin(); }
auto end() const -> typename Container::const_iterator { return c.end(); }
};
} // namespace detail
template <typename T, typename Char>
struct formatter<T, Char,
enable_if_t<detail::is_container_adaptor_like<T>::value>>
: formatter<detail::all<typename T::container_type>, Char> {
using all = detail::all<typename T::container_type>;
template <typename FormatContext>
auto format(const T& t, FormatContext& ctx) const -> decltype(ctx.out()) {
struct getter : T {
static auto get(const T& t) -> all {
return {t.*(&getter::c)}; // Access c through the derived class.
}
};
return formatter<all>::format(getter::get(t), ctx);
}
};
FMT_BEGIN_EXPORT
/**
\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 auto join(const std::tuple<T...>& tuple, string_view sep)
-> tuple_join_view<char, T...> {
return {tuple, sep};
}
template <typename... T>
FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple,
basic_string_view<wchar_t> sep)
-> tuple_join_view<wchar_t, T...> {
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>
auto join(std::initializer_list<T> list, string_view sep)
-> join_view<const T*, const T*> {
return join(std::begin(list), std::end(list), sep);
}
FMT_END_EXPORT
FMT_END_NAMESPACE
#endif // FMT_RANGES_H_