Remove unnecessary usages of nostd::type_traits in API.

api/include/opentelemetry/common/key_value_iterable_view.h

@@ -5,12 +5,12 @@
 
 #include <iterator>
 #include <utility>
+#include <type_traits>
 
 #include "opentelemetry/common/key_value_iterable.h"
 #include "opentelemetry/nostd/function_ref.h"
 #include "opentelemetry/nostd/span.h"
 #include "opentelemetry/nostd/string_view.h"
-#include "opentelemetry/nostd/type_traits.h"
 #include "opentelemetry/nostd/utility.h"
 #include "opentelemetry/version.h"
 
@@ -77,7 +77,7 @@ class KeyValueIterableView final : public KeyValueIterable
  const T *container_;
 };
 
-template <class T, nostd::enable_if_t<detail::is_key_value_iterable<T>::value> * = nullptr>
+template <class T, std::enable_if_t<detail::is_key_value_iterable<T>::value> * = nullptr>
 KeyValueIterableView<T> MakeKeyValueIterableView(const T &container) noexcept
 {
  return KeyValueIterableView<T>(container);
@@ -130,7 +130,7 @@ inline static const common::KeyValueIterable &MakeAttributes(
  */
 template <
  class ArgumentType,
- nostd::enable_if_t<common::detail::is_key_value_iterable<ArgumentType>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<ArgumentType>::value> * = nullptr>
 inline static common::KeyValueIterableView<ArgumentType> MakeAttributes(
  const ArgumentType &arg) noexcept
 {

api/include/opentelemetry/logs/logger_provider.h

@@ -3,12 +3,13 @@
 
 #pragma once
 
+#include <type_traits>
+
 #include "opentelemetry/common/key_value_iterable.h"
 #include "opentelemetry/common/key_value_iterable_view.h"
 #include "opentelemetry/nostd/shared_ptr.h"
 #include "opentelemetry/nostd/span.h"
 #include "opentelemetry/nostd/string_view.h"
-#include "opentelemetry/nostd/type_traits.h"
 #include "opentelemetry/version.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
@@ -56,7 +57,7 @@ class OPENTELEMETRY_EXPORT LoggerProvider
  }
 
  template <class T,
- nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
  nostd::shared_ptr<Logger> GetLogger(nostd::string_view logger_name,
  nostd::string_view library_name,
  nostd::string_view library_version,

api/include/opentelemetry/logs/logger_type_traits.h

@@ -13,7 +13,6 @@
 #include "opentelemetry/logs/log_record.h"
 #include "opentelemetry/logs/severity.h"
 #include "opentelemetry/nostd/string_view.h"
-#include "opentelemetry/nostd/type_traits.h"
 #include "opentelemetry/trace/span_context.h"
 #include "opentelemetry/trace/span_id.h"
 #include "opentelemetry/trace/trace_flags.h"
@@ -146,7 +145,7 @@ template <class ValueType>
 struct LogRecordSetterTrait
 {
  template <class ArgumentType,
- nostd::enable_if_t<std::is_convertible<ArgumentType, nostd::string_view>::value ||
+ std::enable_if_t<std::is_convertible<ArgumentType, nostd::string_view>::value ||
  std::is_convertible<ArgumentType, common::AttributeValue>::value,
  void> * = nullptr>
  inline static LogRecord *Set(LogRecord *log_record, ArgumentType &&arg) noexcept
@@ -157,7 +156,7 @@ struct LogRecordSetterTrait
  }
 
  template <class ArgumentType,
- nostd::enable_if_t<std::is_base_of<common::KeyValueIterable, ArgumentType>::value, bool>
+ std::enable_if_t<std::is_base_of<common::KeyValueIterable, ArgumentType>::value, bool>
  * = nullptr>
  inline static LogRecord *Set(LogRecord *log_record, ArgumentType &&arg) noexcept
  {
@@ -166,7 +165,7 @@ struct LogRecordSetterTrait
  }
 
  template <class ArgumentType,
- nostd::enable_if_t<common::detail::is_key_value_iterable<ArgumentType>::value, int> * =
+ std::enable_if_t<common::detail::is_key_value_iterable<ArgumentType>::value, int> * =
  nullptr>
  inline static LogRecord *Set(LogRecord *log_record, ArgumentType &&arg) noexcept
  {

api/include/opentelemetry/metrics/meter_provider.h

@@ -3,11 +3,12 @@
 
 #pragma once
 
+#include <type_traits>
+
 #include "opentelemetry/common/key_value_iterable.h"
 #include "opentelemetry/common/key_value_iterable_view.h"
 #include "opentelemetry/nostd/shared_ptr.h"
 #include "opentelemetry/nostd/string_view.h"
-#include "opentelemetry/nostd/type_traits.h"
 #include "opentelemetry/version.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
@@ -98,7 +99,7 @@ class MeterProvider
  * @param[in] attributes Instrumentation scope attributes container
  */
  template <class T,
- nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
  nostd::shared_ptr<Meter> GetMeter(nostd::string_view name,
  nostd::string_view version,
  nostd::string_view schema_url,

api/include/opentelemetry/metrics/observer_result.h

@@ -3,12 +3,13 @@
 
 #pragma once
 
+#include <type_traits>
+
 #include "opentelemetry/common/attribute_value.h"
 #include "opentelemetry/common/key_value_iterable_view.h"
 #include "opentelemetry/nostd/shared_ptr.h"
 #include "opentelemetry/nostd/span.h"
 #include "opentelemetry/nostd/string_view.h"
-#include "opentelemetry/nostd/type_traits.h"
 #include "opentelemetry/nostd/variant.h"
 #include "opentelemetry/version.h"
 
@@ -32,7 +33,7 @@ class ObserverResultT
  virtual void Observe(T value, const common::KeyValueIterable &attributes) noexcept = 0;
 
  template <class U,
- nostd::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
  void Observe(T value, const U &attributes) noexcept
  {
  this->Observe(value, common::KeyValueIterableView<U>{attributes});

api/include/opentelemetry/metrics/sync_instruments.h

@@ -3,12 +3,13 @@
 
 #pragma once
 
+#include <type_traits>
+
 #include "opentelemetry/common/attribute_value.h"
 #include "opentelemetry/common/key_value_iterable_view.h"
 #include "opentelemetry/context/context.h"
 #include "opentelemetry/nostd/span.h"
 #include "opentelemetry/nostd/string_view.h"
-#include "opentelemetry/nostd/type_traits.h"
 #include "opentelemetry/version.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
@@ -64,14 +65,14 @@ class Counter : public SynchronousInstrument
  const context::Context &context) noexcept = 0;
 
  template <class U,
- nostd::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
  void Add(T value, const U &attributes) noexcept
  {
  this->Add(value, common::KeyValueIterableView<U>{attributes});
  }
 
  template <class U,
- nostd::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
  void Add(T value, const U &attributes, const context::Context &context) noexcept
  {
  this->Add(value, common::KeyValueIterableView<U>{attributes}, context);
@@ -121,7 +122,7 @@ class Histogram : public SynchronousInstrument
  virtual void Record(T value, const common::KeyValueIterable &attribute) noexcept = 0;
 
  template <class U,
- nostd::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
  void Record(T value, const U &attributes) noexcept
  {
  this->Record(value, common::KeyValueIterableView<U>{attributes});
@@ -156,7 +157,7 @@ class Histogram : public SynchronousInstrument
  const context::Context &context) noexcept = 0;
 
  template <class U,
- nostd::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
  void Record(T value, const U &attributes, const context::Context &context) noexcept
  {
  this->Record(value, common::KeyValueIterableView<U>{attributes}, context);
@@ -215,14 +216,14 @@ class UpDownCounter : public SynchronousInstrument
  const context::Context &context) noexcept = 0;
 
  template <class U,
- nostd::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
  void Add(T value, const U &attributes) noexcept
  {
  this->Add(value, common::KeyValueIterableView<U>{attributes});
  }
 
  template <class U,
- nostd::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
  void Add(T value, const U &attributes, const context::Context &context) noexcept
  {
  this->Add(value, common::KeyValueIterableView<U>{attributes}, context);

api/include/opentelemetry/nostd/detail/trait.h

@@ -5,7 +5,6 @@
 
 #include <type_traits>
 
-#include "opentelemetry/nostd/type_traits.h"
 #include "opentelemetry/version.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE

api/include/opentelemetry/trace/span.h

@@ -4,12 +4,12 @@
 #pragma once
 
 #include <cstdint>
+#include <type_traits>
 
 #include "opentelemetry/common/attribute_value.h"
 #include "opentelemetry/common/key_value_iterable_view.h"
 #include "opentelemetry/nostd/span.h"
 #include "opentelemetry/nostd/string_view.h"
-#include "opentelemetry/nostd/type_traits.h"
 #include "opentelemetry/trace/span_context.h"
 #include "opentelemetry/trace/span_context_kv_iterable.h"
 #include "opentelemetry/trace/span_context_kv_iterable_view.h"
@@ -96,7 +96,7 @@ class Span
  }
 
  template <class T,
- nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
  void AddEvent(nostd::string_view name,
  common::SystemTimestamp timestamp,
  const T &attributes) noexcept
@@ -105,7 +105,7 @@ class Span
  }
 
  template <class T,
- nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
  void AddEvent(nostd::string_view name, const T &attributes) noexcept
  {
  this->AddEvent(name, common::KeyValueIterableView<T>{attributes});
@@ -159,7 +159,7 @@ class Span
  * @since ABI_VERSION 2
  */
  template <class U,
- nostd::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
  void AddLink(const SpanContext &target, const U &attrs)
  {
  common::KeyValueIterableView<U> view(attrs);
@@ -195,7 +195,7 @@ class Span
  *
  * @since ABI_VERSION 2
  */
- template <class U, nostd::enable_if_t<detail::is_span_context_kv_iterable<U>::value> * = nullptr>
+ template <class U, std::enable_if_t<detail::is_span_context_kv_iterable<U>::value> * = nullptr>
  void AddLinks(const U &links)
  {
  SpanContextKeyValueIterableView<U> view(links);

api/include/opentelemetry/trace/span_context_kv_iterable_view.h

@@ -27,7 +27,7 @@ template <class T>
 inline void take_span_context_kv(SpanContext, opentelemetry::common::KeyValueIterableView<T>)
 {}
 
-template <class T, nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
+template <class T, std::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
 inline void take_span_context_kv(SpanContext, T &)
 {}
 
@@ -94,7 +94,7 @@ class SpanContextKeyValueIterableView final : public SpanContextKeyValueIterable
  }
 
  template <class U,
- nostd::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
  bool do_callback(SpanContext span_context,
  const U &attributes,
  nostd::function_ref<bool(SpanContext, const common::KeyValueIterable &)>

api/include/opentelemetry/trace/tracer.h

@@ -48,7 +48,7 @@ class Tracer
  }
 
  template <class T,
- nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
  nostd::shared_ptr<Span> StartSpan(nostd::string_view name,
  const T &attributes,
  const StartSpanOptions &options = {}) noexcept
@@ -65,8 +65,8 @@ class Tracer
 
  template <class T,
  class U,
- nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr,
- nostd::enable_if_t<detail::is_span_context_kv_iterable<U>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr,
+ std::enable_if_t<detail::is_span_context_kv_iterable<U>::value> * = nullptr>
  nostd::shared_ptr<Span> StartSpan(nostd::string_view name,
  const T &attributes,
  const U &links,
@@ -86,7 +86,7 @@ class Tracer
  }
 
  template <class T,
- nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
  nostd::shared_ptr<Span> StartSpan(
  nostd::string_view name,
  const T &attributes,
@@ -105,7 +105,7 @@ class Tracer
  }
 
  template <class T,
- nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
  nostd::shared_ptr<Span> StartSpan(
  nostd::string_view name,
  std::initializer_list<std::pair<nostd::string_view, common::AttributeValue>> attributes,

api/include/opentelemetry/trace/tracer_provider.h

@@ -97,7 +97,7 @@ class OPENTELEMETRY_EXPORT TracerProvider
  * @param[in] attributes Instrumentation scope attributes container
  */
  template <class T,
- nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
+ std::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
  nostd::shared_ptr<Tracer> GetTracer(nostd::string_view name,
  nostd::string_view version,
  nostd::string_view schema_url,

api/test/trace/key_value_iterable_view_test.cc

@@ -5,7 +5,7 @@
 
 #include <gtest/gtest.h>
 #include <map>
-#include "opentelemetry/nostd/type_traits.h"
+#include <type_traits>
 
 using namespace opentelemetry;
 
@@ -21,7 +21,7 @@ static int TakeKeyValues(const common::KeyValueIterable &iterable)
  return count;
 }
 
-template <class T, nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
+template <class T, std::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
 static int TakeKeyValues(const T &iterable)
 {
  return TakeKeyValues(common::KeyValueIterableView<T>{iterable});