Add vendor/fmt

[lttng-tools.git] / src / vendor / fmt / ostream.h

diff --git a/src/vendor/fmt/ostream.h b/src/vendor/fmt/ostream.h
new file mode 100644 (file)
index 0000000..3d716ec
--- /dev/null
+++ b/src/vendor/fmt/ostream.h
@@ -0,0 +1,135 @@
+// Formatting library for C++ - std::ostream support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_OSTREAM_H_
+#define FMT_OSTREAM_H_
+
+#include <ostream>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+
+template <typename OutputIt, typename Char> class basic_printf_context;
+
+namespace detail {
+
+// Checks if T has a user-defined operator<<.
+template <typename T, typename Char, typename Enable = void>
+class is_streamable {
+ private:
+  template <typename U>
+  static auto test(int)
+      -> bool_constant<sizeof(std::declval<std::basic_ostream<Char>&>()
+                              << std::declval<U>()) != 0>;
+
+  template <typename> static auto test(...) -> std::false_type;
+
+  using result = decltype(test<T>(0));
+
+ public:
+  is_streamable() = default;
+
+  static const bool value = result::value;
+};
+
+// Formatting of built-in types and arrays is intentionally disabled because
+// it's handled by standard (non-ostream) formatters.
+template <typename T, typename Char>
+struct is_streamable<
+    T, Char,
+    enable_if_t<
+        std::is_arithmetic<T>::value || std::is_array<T>::value ||
+        std::is_pointer<T>::value || std::is_same<T, char8_type>::value ||
+        std::is_same<T, std::basic_string<Char>>::value ||
+        std::is_same<T, std_string_view<Char>>::value ||
+        (std::is_convertible<T, int>::value && !std::is_enum<T>::value)>>
+    : std::false_type {};
+
+// Write the content of buf to os.
+// It is a separate function rather than a part of vprint to simplify testing.
+template <typename Char>
+void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
+  const Char* buf_data = buf.data();
+  using unsigned_streamsize = std::make_unsigned<std::streamsize>::type;
+  unsigned_streamsize size = buf.size();
+  unsigned_streamsize max_size = to_unsigned(max_value<std::streamsize>());
+  do {
+    unsigned_streamsize n = size <= max_size ? size : max_size;
+    os.write(buf_data, static_cast<std::streamsize>(n));
+    buf_data += n;
+    size -= n;
+  } while (size != 0);
+}
+
+template <typename Char, typename T>
+void format_value(buffer<Char>& buf, const T& value,
+                  locale_ref loc = locale_ref()) {
+  auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
+  auto&& output = std::basic_ostream<Char>(&format_buf);
+#if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
+  if (loc) output.imbue(loc.get<std::locale>());
+#endif
+  output << value;
+  output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
+  buf.try_resize(buf.size());
+}
+
+// Formats an object of type T that has an overloaded ostream operator<<.
+template <typename T, typename Char>
+struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
+    : private formatter<basic_string_view<Char>, Char> {
+  using formatter<basic_string_view<Char>, Char>::parse;
+
+  template <typename OutputIt>
+  auto format(const T& value, basic_format_context<OutputIt, Char>& ctx)
+      -> OutputIt {
+    auto buffer = basic_memory_buffer<Char>();
+    format_value(buffer, value, ctx.locale());
+    return formatter<basic_string_view<Char>, Char>::format(
+        {buffer.data(), buffer.size()}, ctx);
+  }
+
+  // DEPRECATED!
+  template <typename OutputIt>
+  auto format(const T& value, basic_printf_context<OutputIt, Char>& ctx)
+      -> OutputIt {
+    auto buffer = basic_memory_buffer<Char>();
+    format_value(buffer, value, ctx.locale());
+    return std::copy(buffer.begin(), buffer.end(), ctx.out());
+  }
+};
+}  // namespace detail
+
+FMT_MODULE_EXPORT
+template <typename Char>
+void vprint(std::basic_ostream<Char>& os, basic_string_view<Char> format_str,
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  auto buffer = basic_memory_buffer<Char>();
+  detail::vformat_to(buffer, format_str, args);
+  detail::write_buffer(os, buffer);
+}
+
+/**
+  \rst
+  Prints formatted data to the stream *os*.
+
+  **Example**::
+
+    fmt::print(cerr, "Don't {}!", "panic");
+  \endrst
+ */
+FMT_MODULE_EXPORT
+template <typename S, typename... Args,
+          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
+void print(std::basic_ostream<Char>& os, const S& format_str, Args&&... args) {
+  vprint(os, to_string_view(format_str),
+         fmt::make_args_checked<Args...>(format_str, args...));
+}
+FMT_END_NAMESPACE
+
+#endif  // FMT_OSTREAM_H_