Remove unneeded stuff

CMakeLists.txt

@@ -33,6 +33,8 @@ if (MASTER_PROJECT AND NOT CMAKE_BUILD_TYPE)
   set(CMAKE_BUILD_TYPE Release CACHE STRING ${doc})
 endif ()
 
+option(FMT_USE_TEXT "Use the text library." OFF)
+
 option(FMT_PEDANTIC "Enable extra warnings and expensive tests." OFF)
 option(FMT_WERROR "Halt the compilation with an error on compiler warnings."
        OFF)
@@ -160,6 +162,10 @@ if (HAVE_OPEN)
   set(FMT_SOURCES ${FMT_SOURCES} src/posix.cc)
 endif ()
 
+if (FMT_USE_TEXT)
+  set(FMT_SOURCES ${FMT_SOURCES} src/text/grapheme_break.cpp)
+endif ()
+
 add_library(fmt ${FMT_SOURCES} ${FMT_HEADERS} README.rst ChangeLog.rst)
 add_library(fmt::fmt ALIAS fmt)
 
@@ -180,6 +186,11 @@ target_include_directories(fmt PUBLIC
   $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
   $<INSTALL_INTERFACE:include>)
 
+if (FMT_USE_TEXT)
+  target_include_directories(fmt PUBLIC
+    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/src/text>)
+endif ()
+
 set_target_properties(fmt PROPERTIES
   VERSION ${FMT_VERSION} SOVERSION ${CPACK_PACKAGE_VERSION_MAJOR}
   DEBUG_POSTFIX d)

include/fmt/format.h

@@ -45,6 +45,14 @@
 
 #include "core.h"
 
+#ifndef FMT_USE_TEXT
+#  define FMT_USE_TEXT 0
+#endif
+#if FMT_USE_TEXT
+#  include <boost/text/grapheme_break.hpp>
+#  include <boost/text/transcode_iterator.hpp>
+#endif
+
 #ifdef __clang__
 #  define FMT_CLANG_VERSION (__clang_major__ * 100 + __clang_minor__)
 #else
@@ -415,11 +423,6 @@ class output_range {
   sentinel end() const { return {}; }  // Sentinel is not used yet.
 };
 
-template <typename Char>
-inline size_t count_code_points(basic_string_view<Char> s) {
-  return s.size();
-}
-
 // Counts the number of code points in a UTF-8 string.
 inline size_t count_code_points(basic_string_view<char8_t> s) {
   const char8_t* data = s.data();
@@ -912,6 +915,59 @@ inline It format_uint(It out, UInt value, int num_digits, bool upper = false) {
   return internal::copy_str<Char>(buffer, buffer + num_digits, out);
 }
 
+template <typename Char>
+inline size_t compute_width(basic_string_view<Char> s) {
+  return s.size();
+}
+
+inline size_t compute_width(string_view s) {
+#if FMT_USE_TEXT
+  basic_memory_buffer<uint32_t> code_points;
+  const char* s_end = s.data() + s.size();
+  boost::text::utf_8_to_32_iterator<const char*> begin(s.data(), s.data(),
+                                                       s_end),
+      end(s.data(), s_end, s_end);
+  for (auto it = begin; it != end; ++it) code_points.push_back(*it);
+  size_t width = 0;
+  for (auto it = code_points.begin(), end = code_points.end(); it != end;
+       it = boost::text::next_grapheme_break(it, end)) {
+    auto cp = *it;
+    // Based on http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c by Markus Kuhn.
+    width +=
+        1 + (cp >= 0x1100 &&
+             (cp <= 0x115f ||  // Hangul Jamo init. consonants
+              cp == 0x2329 ||  // LEFT-POINTING ANGLE BRACKET〈
+              cp == 0x232a ||  // RIGHT-POINTING ANGLE BRACKET 〉
+              // CJK ... Yi except Unicode Character “〿”:
+              (cp >= 0x2e80 && cp <= 0xa4cf && cp != 0x303f) ||
+              (cp >= 0xac00 && cp <= 0xd7a3) ||  // Hangul Syllables
+              (cp >= 0xf900 && cp <= 0xfaff) ||  // CJK Compatibility Ideographs
+              (cp >= 0xfe10 && cp <= 0xfe19) ||  // Vertical Forms
+              (cp >= 0xfe30 && cp <= 0xfe6f) ||  // CJK Compatibility Forms
+              (cp >= 0xff00 && cp <= 0xff60) ||  // Fullwidth Forms
+              (cp >= 0xffe0 && cp <= 0xffe6) ||  // Fullwidth Forms
+              (cp >= 0x20000 && cp <= 0x2fffd) ||  // CJK
+              (cp >= 0x30000 && cp <= 0x3fffd) ||
+              // Miscellaneous Symbols and Pictographs + Emoticons:
+              (cp >= 0x1f300 && cp <= 0x1f64f) ||
+              // Supplemental Symbols and Pictographs:
+              (cp >= 0x1f900 && cp <= 0x1f9ff)));
+  }
+  return width;
+#else
+  return s.size();
+#endif  // FMT_USE_TEXT
+}
+
+inline size_t compute_width(basic_string_view<char8_t> s) {
+#if FMT_USE_TEXT
+  return compute_width(
+      string_view(reinterpret_cast<const char*>(s.data(), s.size())));
+#else
+  return count_code_points(s);
+#endif  // FMT_USE_TEXT
+}
+
 #ifndef _WIN32
 #  define FMT_USE_WINDOWS_H 0
 #elif !defined(FMT_USE_WINDOWS_H)
@@ -1583,7 +1639,7 @@ template <typename Range> class basic_writer {
 
     size_t size() const { return size_; }
     size_t width() const {
-      return internal::count_code_points(basic_string_view<Char>(s, size_));
+      return internal::compute_width(basic_string_view<Char>(s, size_));
     }
 
     template <typename It> void operator()(It&& it) const {

src/text/boost/assert.hpp

@@ -0,0 +1,4 @@
+#ifndef BOOST_ASSERT
+#include <assert.h>
+# define BOOST_ASSERT(condition) assert(condition)
+#endif

src/text/boost/container/small_vector.hpp

@@ -0,0 +1,13 @@
+#ifndef TEXT_BOOST_CONTAINER_SMALL_VECTOR_HPP
+#define TEXT_BOOST_CONTAINER_SMALL_VECTOR_HPP
+
+#include <vector>
+
+namespace boost {
+namespace container {
+template <typename T, size_t>
+using small_vector = std::vector<T>;
+}
+}
+
+#endif  // TEXT_BOOST_CONTAINER_SMALL_VECTOR_HPP

src/text/boost/text/config.hpp

@@ -0,0 +1,102 @@
+#ifndef BOOST_TEXT_CONFIG_HPP
+#define BOOST_TEXT_CONFIG_HPP
+
+
+/** There are ICU-based implementations of many operations, but those are only
+    defined when BOOST_TEXT_HAS_ICU is nonzero.  If you define this, you must
+    make sure the the ICU headers are in your path, and that your build
+    properly links in ICU. */
+#ifndef BOOST_TEXT_HAS_ICU
+#    define BOOST_TEXT_HAS_ICU 0
+#endif
+
+/** There are ICU-based implementations of many operations, but those are only
+    used when BOOST_TEXT_HAS_ICU and BOOST_TEXT_USE_ICU are both nonzero. */
+#ifndef BOOST_TEXT_USE_ICU
+#    define BOOST_TEXT_USE_ICU 0
+#endif
+
+/** When you insert into a rope, the incoming sequence may be inserted as a
+    new segment, or if it falls within an existing string-segment, it may be
+    inserted into the string object used to represent that segment.  This only
+    happens if the incoming sequence will fit within the existing segment's
+    capacity, or if the segment is smaller than a certain limit.
+    BOOST_TEXT_STRING_INSERT_MAX is that limit. */
+#ifndef BOOST_TEXT_STRING_INSERT_MAX
+#    define BOOST_TEXT_STRING_INSERT_MAX 4096
+#endif
+
+#ifndef BOOST_TEXT_DOXYGEN
+
+// Nothing before GCC 6 has proper C++14 constexpr support.
+#if defined(__GNUC__) && __GNUC__ < 6 && !defined(__clang__)
+#    define BOOST_TEXT_CXX14_CONSTEXPR
+#    define BOOST_TEXT_NO_CXX14_CONSTEXPR
+#elif defined(_MSC_VER) && _MSC_VER <= 1915
+#    define BOOST_TEXT_CXX14_CONSTEXPR
+#    define BOOST_TEXT_NO_CXX14_CONSTEXPR
+#else
+#    define BOOST_TEXT_CXX14_CONSTEXPR
+#    if defined(BOOST_NO_CXX14_CONSTEXPR)
+#        define BOOST_TEXT_NO_CXX14_CONSTEXPR
+#    endif
+#endif
+
+// Implements separate compilation features as described in
+// http://www.boost.org/more/separate_compilation.html
+
+//  normalize macros
+
+#if !defined(BOOST_TEXT_DYN_LINK) && !defined(BOOST_TEXT_STATIC_LINK) &&       \
+    !defined(BOOST_ALL_DYN_LINK) && !defined(BOOST_ALL_STATIC_LINK)
+#    define BOOST_TEXT_STATIC_LINK
+#endif
+
+#if defined(BOOST_ALL_DYN_LINK) && !defined(BOOST_TEXT_DYN_LINK)
+#    define BOOST_TEXT_DYN_LINK
+#elif defined(BOOST_ALL_STATIC_LINK) && !defined(BOOST_TEXT_STATIC_LINK)
+#    define BOOST_TEXT_STATIC_LINK
+#endif
+
+#if defined(BOOST_TEXT_DYN_LINK) && defined(BOOST_TEXT_STATIC_LINK)
+#    error Must not define both BOOST_TEXT_DYN_LINK and BOOST_TEXT_STATIC_LINK
+#endif
+
+//  enable dynamic or static linking as requested
+
+#if defined(BOOST_ALL_DYN_LINK) || defined(BOOST_TEXT_DYN_LINK)
+#    if defined(BOOST_TEXT_SOURCE)
+#        define BOOST_TEXT_DECL BOOST_SYMBOL_EXPORT
+#    else
+#        define BOOST_TEXT_DECL BOOST_SYMBOL_IMPORT
+#    endif
+#else
+#    define BOOST_TEXT_DECL
+#endif
+
+#if 0 // TODO: Disabled for now.
+//  enable automatic library variant selection
+
+#if !defined(BOOST_TEXT_SOURCE) && !defined(BOOST_ALL_NO_LIB) &&               \
+    !defined(BOOST_TEXT_NO_LIB)
+//
+// Set the name of our library, this will get undef'ed by auto_link.hpp
+// once it's done with it:
+//
+#define BOOST_LIB_NAME boost_text
+//
+// If we're importing code from a dll, then tell auto_link.hpp about it:
+//
+#if defined(BOOST_ALL_DYN_LINK) || defined(BOOST_TEXT_DYN_LINK)
+#    define BOOST_DYN_LINK
+#endif
+//
+// And include the header that does the work:
+//
+#include <boost/config/auto_link.hpp>
+#endif  // auto-linking disabled
+#endif
+
+#endif // doxygen
+
+#endif

src/text/boost/text/detail/break_prop_iter.hpp

@@ -0,0 +1,51 @@
+#ifndef BOOST_TEXT_DETAIL_BREAK_PROP_ITER_HPP
+#define BOOST_TEXT_DETAIL_BREAK_PROP_ITER_HPP
+
+#include <boost/text/detail/lzw.hpp>
+
+#include <unordered_map>
+
+
+namespace boost { namespace text { namespace detail {
+
+    template<typename Enum>
+    struct lzw_to_break_prop_iter
+    {
+        using value_type = std::pair<uint32_t, Enum>;
+        using difference_type = int;
+        using pointer = unsigned char *;
+        using reference = unsigned char &;
+        using iterator_category = std::output_iterator_tag;
+        using buffer_t = container::small_vector<unsigned char, 256>;
+
+        lzw_to_break_prop_iter(
+            std::unordered_map<uint32_t, Enum> & map, buffer_t & buf) :
+            map_(&map),
+            buf_(&buf)
+        {}
+
+        lzw_to_break_prop_iter & operator=(unsigned char c)
+        {
+            buf_->push_back(c);
+            auto const element_bytes = 4;
+            auto it = buf_->begin();
+            for (auto end = buf_->end() - buf_->size() % element_bytes;
+                 it != end;
+                 it += element_bytes) {
+                (*map_)[bytes_to_cp(&*it)] = Enum(*(it + 3));
+            }
+            buf_->erase(buf_->begin(), it);
+            return *this;
+        }
+        lzw_to_break_prop_iter & operator*() { return *this; }
+        lzw_to_break_prop_iter & operator++() { return *this; }
+        lzw_to_break_prop_iter & operator++(int) { return *this; }
+
+    private:
+        std::unordered_map<uint32_t, Enum> * map_;
+        buffer_t * buf_;
+    };
+
+}}}
+
+#endif

src/text/boost/text/detail/lzw.hpp

@@ -0,0 +1,104 @@
+#ifndef BOOST_TEXT_DETAIL_LZW_HPP
+#define BOOST_TEXT_DETAIL_LZW_HPP
+
+#include <boost/assert.hpp>
+#include <boost/container/small_vector.hpp>
+
+#include <vector>
+
+
+namespace boost { namespace text { namespace detail {
+
+    inline uint32_t bytes_to_uint32_t(unsigned char const * chars)
+    {
+        return chars[0] << 24 | chars[1] << 16 | chars[2] << 8 | chars[3] << 0;
+    }
+
+    inline uint32_t bytes_to_cp(unsigned char const * chars)
+    {
+        return chars[0] << 16 | chars[1] << 8 | chars[2] << 0;
+    }
+
+    inline uint32_t bytes_to_uint16_t(unsigned char const * chars)
+    {
+        return chars[0] << 8 | chars[1] << 0;
+    }
+
+    enum : uint16_t { no_predecessor = 0xffff, no_value = 0xffff };
+
+    struct lzw_reverse_table_element
+    {
+        lzw_reverse_table_element(
+            uint16_t pred = no_predecessor, uint16_t value = no_value) :
+            pred_(pred),
+            value_(value)
+        {}
+        uint16_t pred_;
+        uint16_t value_;
+    };
+
+    using lzw_reverse_table = std::vector<lzw_reverse_table_element>;
+
+    template<typename OutIter>
+    OutIter
+    copy_table_entry(lzw_reverse_table const & table, uint16_t i, OutIter out)
+    {
+        *out++ = table[i].value_;
+        while (table[i].pred_ != no_predecessor) {
+            i = table[i].pred_;
+            *out++ = table[i].value_;
+        }
+        return out;
+    }
+
+    // Hardcoded to 16 bits.  Takes unsigned 16-bit LZW-compressed values as
+    // input and writes the decompressed unsigned char values to out.
+    template<typename Iter, typename OutIter>
+    OutIter lzw_decompress(Iter first, Iter last, OutIter out)
+    {
+        lzw_reverse_table reverse_table(1 << 16);
+        for (uint16_t i = 0; i < 256u; ++i) {
+            reverse_table[i].value_ = i;
+        }
+
+        container::small_vector<unsigned char, 256> table_entry;
+
+        uint32_t next_table_value = 256;
+        uint32_t const end_table_value = 1 << 16;
+
+        uint16_t prev_code = *first++;
+        BOOST_ASSERT(prev_code < 256);
+        unsigned char c = (unsigned char)prev_code;
+        table_entry.push_back(c);
+        *out++ = table_entry;
+
+        while (first != last) {
+            uint16_t const code = *first++;
+
+            table_entry.clear();
+            if (reverse_table[code].value_ == no_value) {
+                table_entry.push_back(c);
+                copy_table_entry(
+                    reverse_table, prev_code, std::back_inserter(table_entry));
+            } else {
+                copy_table_entry(
+                    reverse_table, code, std::back_inserter(table_entry));
+            }
+
+            *out++ = table_entry;
+            c = table_entry.back();
+
+            if (next_table_value < end_table_value) {
+                reverse_table[next_table_value++] =
+                    lzw_reverse_table_element{prev_code, c};
+            }
+
+            prev_code = code;
+        }
+
+        return out;
+    }
+
+}}}
+
+#endif

src/text/boost/text/grapheme_break.hpp

@@ -0,0 +1,224 @@
+#ifndef BOOST_TEXT_GRAPHEME_BREAK_HPP
+#define BOOST_TEXT_GRAPHEME_BREAK_HPP
+
+#include <array>
+#include <unordered_map>
+
+#include <stdint.h>
+
+#define BOOST_TEXT_DECL
+
+namespace boost { namespace text {
+
+    /** Analogue of `std::find()` that finds the last value `v` in `[first,
+        last)` for which `p(v)` is true. */
+    template<typename BidiIter, typename Pred>
+    BidiIter find_if_backward(BidiIter first, BidiIter last, Pred p)
+    {
+        auto it = last;
+        while (it != first) {
+            if (p(*--it))
+                return it;
+        }
+        return last;
+    }
+
+    /** The grapheme properties defined by Unicode. */
+    enum class grapheme_property {
+        Other,
+        CR,
+        LF,
+        Control,
+        Extend,
+        Regional_Indicator,
+        Prepend,
+        SpacingMark,
+        L,
+        V,
+        T,
+        LV,
+        LVT,
+        ExtPict,
+        ZWJ
+    };
+
+    namespace detail {
+        struct grapheme_prop_interval
+        {
+            uint32_t lo_;
+            uint32_t hi_;
+            grapheme_property prop_;
+        };
+
+        inline bool operator<(
+            grapheme_prop_interval lhs, grapheme_prop_interval rhs) noexcept
+        {
+            return lhs.hi_ <= rhs.lo_;
+        }
+
+        BOOST_TEXT_DECL std::array<grapheme_prop_interval, 6> const &
+        make_grapheme_prop_intervals();
+        BOOST_TEXT_DECL std::unordered_map<uint32_t, grapheme_property>
+        make_grapheme_prop_map();
+    }
+
+    /** Returns the grapheme property associated with code point `cp`. */
+    inline grapheme_property grapheme_prop(uint32_t cp) noexcept
+    {
+        static auto const map = detail::make_grapheme_prop_map();
+        static auto const intervals = detail::make_grapheme_prop_intervals();
+
+        auto const it = map.find(cp);
+        if (it == map.end()) {
+            auto const it2 = std::lower_bound(
+                intervals.begin(),
+                intervals.end(),
+                detail::grapheme_prop_interval{cp, cp + 1});
+            if (it2 == intervals.end() || cp < it2->lo_ || it2->hi_ <= cp)
+                return grapheme_property::Other;
+            return it2->prop_;
+        }
+        return it->second;
+    }
+
+    namespace detail {
+        inline bool skippable(grapheme_property prop) noexcept
+        {
+            return prop == grapheme_property::Extend;
+        }
+
+        enum class grapheme_break_emoji_state_t {
+            none,
+            first_emoji, // Indicates that prop points to an odd-count
+                         // emoji.
+            second_emoji // Indicates that prop points to an even-count
+                         // emoji.
+        };
+
+        template<typename CPIter>
+        struct grapheme_break_state
+        {
+            CPIter it;
+
+            grapheme_property prev_prop;
+            grapheme_property prop;
+
+            grapheme_break_emoji_state_t emoji_state;
+        };
+
+        template<typename CPIter>
+        grapheme_break_state<CPIter> next(grapheme_break_state<CPIter> state)
+        {
+            ++state.it;
+            state.prev_prop = state.prop;
+            return state;
+        }
+
+        template<typename CPIter>
+        grapheme_break_state<CPIter> prev(grapheme_break_state<CPIter> state)
+        {
+            --state.it;
+            state.prop = state.prev_prop;
+            return state;
+        }
+
+        template<typename CPIter>
+        bool gb11_prefix(CPIter first, CPIter prev_it)
+        {
+            auto final_prop = grapheme_property::Other;
+            find_if_backward(first, prev_it, [&final_prop](uint32_t cp) {
+                final_prop = grapheme_prop(cp);
+                return final_prop != grapheme_property::Extend;
+            });
+            return final_prop == grapheme_property::ExtPict;
+        }
+
+        inline bool table_grapheme_break(
+            grapheme_property lhs, grapheme_property rhs) noexcept
+        {
+            // Note that RI.RI was changed to '1' since that case is handled
+            // in the grapheme break FSM.
+
+            // clang-format off
+// See chart at https://unicode.org/Public/11.0.0/ucd/auxiliary/GraphemeBreakTest.html .
+constexpr std::array<std::array<bool, 15>, 15> grapheme_breaks = {{
+//   Other CR LF Ctrl Ext RI Pre SpcMk L  V  T  LV LVT ExtPict ZWJ
+    {{1,   1, 1, 1,   0,  1, 1,  0,    1, 1, 1, 1, 1,  1,      0}}, // Other
+    {{1,   1, 0, 1,   1,  1, 1,  1,    1, 1, 1, 1, 1,  1,      1}}, // CR
+    {{1,   1, 1, 1,   1,  1, 1,  1,    1, 1, 1, 1, 1,  1,      1}}, // LF
+    {{1,   1, 1, 1,   1,  1, 1,  1,    1, 1, 1, 1, 1,  1,      1}}, // Control
+    {{1,   1, 1, 1,   0,  1, 1,  0,    1, 1, 1, 1, 1,  1,      0}}, // Extend
+    {{1,   1, 1, 1,   0,  1, 1,  0,    1, 1, 1, 1, 1,  1,      0}}, // RI
+    {{0,   1, 1, 1,   0,  0, 0,  0,    0, 0, 0, 0, 0,  0,      0}}, // Prepend
+    {{1,   1, 1, 1,   0,  1, 1,  0,    1, 1, 1, 1, 1,  1,      0}}, // SpacingMark
+    {{1,   1, 1, 1,   0,  1, 1,  0,    0, 0, 1, 0, 0,  1,      0}}, // L
+    {{1,   1, 1, 1,   0,  1, 1,  0,    1, 0, 0, 1, 1,  1,      0}}, // V
+    {{1,   1, 1, 1,   0,  1, 1,  0,    1, 1, 0, 1, 1,  1,      0}}, // T
+    {{1,   1, 1, 1,   0,  1, 1,  0,    1, 0, 0, 1, 1,  1,      0}}, // LV
+    {{1,   1, 1, 1,   0,  1, 1,  0,    1, 1, 0, 1, 1,  1,      0}}, // LVT
+    {{1,   1, 1, 1,   0,  1, 1,  0,    1, 1, 1, 1, 1,  1,      0}}, // ExtPict
+    {{1,   1, 1, 1,   0,  1, 1,  0,    1, 1, 1, 1, 1,  1,      0}}, // ZWJ
+
+}};
+            // clang-format on
+            auto const lhs_int = static_cast<int>(lhs);
+            auto const rhs_int = static_cast<int>(rhs);
+            return grapheme_breaks[lhs_int][rhs_int];
+        }
+    }
+
+    template<typename CPIter, typename Sentinel>
+    CPIter next_grapheme_break(CPIter first, Sentinel last) noexcept
+    {
+        if (first == last)
+            return first;
+
+        detail::grapheme_break_state<CPIter> state;
+        state.it = first;
+
+        if (++state.it == last)
+            return state.it;
+
+        state.prev_prop = grapheme_prop(*std::prev(state.it));
+        state.prop = grapheme_prop(*state.it);
+
+        state.emoji_state =
+            state.prev_prop == grapheme_property::Regional_Indicator
+                ? detail::grapheme_break_emoji_state_t::first_emoji
+                : detail::grapheme_break_emoji_state_t::none;
+
+        for (; state.it != last; state = next(state)) {
+            state.prop = grapheme_prop(*state.it);
+
+            // GB11
+            if (state.prev_prop == grapheme_property::ZWJ &&
+                state.prop == grapheme_property::ExtPict &&
+                detail::gb11_prefix(first, std::prev(state.it))) {
+                continue;
+            }
+
+            if (state.emoji_state ==
+                detail::grapheme_break_emoji_state_t::first_emoji) {
+                if (state.prop == grapheme_property::Regional_Indicator) {
+                    state.emoji_state =
+                        detail::grapheme_break_emoji_state_t::none;
+                    continue;
+                } else {
+                    state.emoji_state =
+                        detail::grapheme_break_emoji_state_t::none;
+                }
+            } else if (state.prop == grapheme_property::Regional_Indicator) {
+                state.emoji_state =
+                    detail::grapheme_break_emoji_state_t::first_emoji;
+            }
+
+            if (detail::table_grapheme_break(state.prev_prop, state.prop))
+                return state.it;
+        }
+
+        return state.it;
+    }
+
+}}
+
+#endif

src/text/boost/throw_exception.hpp

@@ -0,0 +1,9 @@
+#ifndef TEXT_BOOST_THROW_EXCEPTION_HPP
+#define TEXT_BOOST_THROW_EXCEPTION_HPP
+
+namespace boost {
+template <typename E>
+void throw_exception(const E& e) { throw e; }
+}
+
+#endif  // TEXT_BOOST_THROW_EXCEPTION_HPP