added bundled fmt 5.x

include/spdlog/fmt/bundled/ostream.h

@@ -0,0 +1,171 @@
+// Formatting library for C++ - std::ostream support
+//
+// Copyright (c) 2012 - 2016, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_OSTREAM_H_
+#define FMT_OSTREAM_H_
+
+#include "format.h"
+#include <ostream>
+
+FMT_BEGIN_NAMESPACE
+namespace internal {
+
+template<class Char>
+class formatbuf : public std::basic_streambuf<Char>
+{
+private:
+    typedef typename std::basic_streambuf<Char>::int_type int_type;
+    typedef typename std::basic_streambuf<Char>::traits_type traits_type;
+
+    basic_buffer<Char> &buffer_;
+
+public:
+    formatbuf(basic_buffer<Char> &buffer)
+        : buffer_(buffer)
+    {
+    }
+
+protected:
+    // The put-area is actually always empty. This makes the implementation
+    // simpler and has the advantage that the streambuf and the buffer are always
+    // in sync and sputc never writes into uninitialized memory. The obvious
+    // disadvantage is that each call to sputc always results in a (virtual) call
+    // to overflow. There is no disadvantage here for sputn since this always
+    // results in a call to xsputn.
+
+    int_type overflow(int_type ch = traits_type::eof()) FMT_OVERRIDE
+    {
+        if (!traits_type::eq_int_type(ch, traits_type::eof()))
+            buffer_.push_back(static_cast<Char>(ch));
+        return ch;
+    }
+
+    std::streamsize xsputn(const Char *s, std::streamsize count) FMT_OVERRIDE
+    {
+        buffer_.append(s, s + count);
+        return count;
+    }
+};
+
+template<typename Char>
+struct test_stream : std::basic_ostream<Char>
+{
+private:
+    struct null;
+    // Hide all operator<< from std::basic_ostream<Char>.
+    void operator<<(null);
+};
+
+// Checks if T has a user-defined operator<< (e.g. not a member of std::ostream).
+template<typename T, typename Char>
+class is_streamable
+{
+private:
+    template<typename U>
+    static decltype(internal::declval<test_stream<Char> &>() << internal::declval<U>(), std::true_type()) test(int);
+
+    template<typename>
+    static std::false_type test(...);
+
+    typedef decltype(test<T>(0)) result;
+
+public:
+    // std::string operator<< is not considered user-defined because we handle strings
+    // specially.
+    static const bool value = result::value && !std::is_same<T, std::string>::value;
+};
+
+// Disable conversion to int if T has an overloaded operator<< which is a free
+// function (not a member of std::ostream).
+template<typename T, typename Char>
+class convert_to_int<T, Char, true>
+{
+public:
+    static const bool value = convert_to_int<T, Char, false>::value && !is_streamable<T, Char>::value;
+};
+
+// Write the content of buf to os.
+template<typename Char>
+void write(std::basic_ostream<Char> &os, basic_buffer<Char> &buf)
+{
+    const Char *data = buf.data();
+    typedef std::make_unsigned<std::streamsize>::type UnsignedStreamSize;
+    UnsignedStreamSize size = buf.size();
+    UnsignedStreamSize max_size = internal::to_unsigned((std::numeric_limits<std::streamsize>::max)());
+    do
+    {
+        UnsignedStreamSize n = size <= max_size ? size : max_size;
+        os.write(data, static_cast<std::streamsize>(n));
+        data += n;
+        size -= n;
+    } while (size != 0);
+}
+
+template<typename Char, typename T>
+void format_value(basic_buffer<Char> &buffer, const T &value)
+{
+    internal::formatbuf<Char> format_buf(buffer);
+    std::basic_ostream<Char> output(&format_buf);
+    output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
+    output << value;
+    buffer.resize(buffer.size());
+}
+
+// Disable builtin formatting of enums and use operator<< instead.
+template<typename T>
+struct format_enum<T, typename std::enable_if<std::is_enum<T>::value>::type> : std::false_type
+{
+};
+} // namespace internal
+
+// Formats an object of type T that has an overloaded ostream operator<<.
+template<typename T, typename Char>
+struct formatter<T, Char, typename std::enable_if<internal::is_streamable<T, Char>::value>::type> : formatter<basic_string_view<Char>, Char>
+{
+
+    template<typename Context>
+    auto format(const T &value, Context &ctx) -> decltype(ctx.out())
+    {
+        basic_memory_buffer<Char> buffer;
+        internal::format_value(buffer, value);
+        basic_string_view<Char> str(buffer.data(), buffer.size());
+        formatter<basic_string_view<Char>, Char>::format(str, ctx);
+        return ctx.out();
+    }
+};
+
+template<typename Char>
+inline void vprint(
+    std::basic_ostream<Char> &os, basic_string_view<Char> format_str, basic_format_args<typename buffer_context<Char>::type> args)
+{
+    basic_memory_buffer<Char> buffer;
+    vformat_to(buffer, format_str, args);
+    internal::write(os, buffer);
+}
+/**
+  \rst
+  Prints formatted data to the stream *os*.
+
+  **Example**::
+
+    fmt::print(cerr, "Don't {}!", "panic");
+  \endrst
+ */
+template<typename... Args>
+inline void print(std::ostream &os, string_view format_str, const Args &... args)
+{
+    vprint<char>(os, format_str, make_format_args<format_context>(args...));
+}
+
+template<typename... Args>
+inline void print(std::wostream &os, wstring_view format_str, const Args &... args)
+{
+    vprint<wchar_t>(os, format_str, make_format_args<wformat_context>(args...));
+}
+FMT_END_NAMESPACE
+
+#endif // FMT_OSTREAM_H_