Apply some clang-tidy fixes.

This patch was generated using clang-tidy:

  clang-tidy -checks="-*,..." -fix

The following set of checks was enabled:

  modernize-use-nullptr,modernize-deprecated-headers,modernize-make-shared,
  modernize-redundant-void-arg,modernize-use-bool-literals,
  modernize-use-emplace,modernize-use-equals-default,
  google-readability-namespace-comments,misc-unused-using-decls

Add NOLINT to have clang-tidy (among other tools) ignore some lines
that are not meant to be changed.

pv/binding/decoder.cpp

@@ -31,7 +31,6 @@
 #include <pv/prop/string.hpp>
 
 using boost::none;
-using std::make_pair;
 using std::map;
 using std::pair;
 using std::shared_ptr;
@@ -97,7 +96,7 @@ shared_ptr<Property> Decoder::bind_enum(
 	vector< pair<Glib::VariantBase, QString> > values;
 	for (GSList *l = option->values; l; l = l->next) {
 		Glib::VariantBase var = Glib::VariantBase((GVariant*)l->data, true);
-		values.push_back(make_pair(var, print_gvariant(var)));
+		values.emplace_back(var, print_gvariant(var));
 	}
 
 	return shared_ptr<Property>(new Enum(name, desc, values, getter, setter));

pv/binding/device.cpp

@@ -32,7 +32,6 @@
 using boost::optional;
 
 using std::function;
-using std::make_pair;
 using std::pair;
 using std::set;
 using std::shared_ptr;
@@ -157,7 +156,7 @@ void Device::bind_enum(const QString &name, const QString &desc,
 
 		vector< pair<Glib::VariantBase, QString> > values;
 		while ((iter.next_value(gvar)))
-			values.push_back(make_pair(gvar, printer(gvar)));
+			values.emplace_back(gvar, printer(gvar));
 
 		properties_.push_back(shared_ptr<Property>(new Enum(name, desc, values,
 			getter, setter)));

pv/binding/inputoutput.cpp

@@ -35,7 +35,6 @@
 
 using boost::none;
 
-using std::make_pair;
 using std::map;
 using std::pair;
 using std::shared_ptr;
@@ -111,7 +110,7 @@ shared_ptr<Property> InputOutput::bind_enum(
 {
 	vector< pair<VariantBase, QString> > enum_vals;
 	for (VariantBase var : values)
-		enum_vals.push_back(make_pair(var, print_gvariant(var)));
+		enum_vals.emplace_back(var, print_gvariant(var));
 	return shared_ptr<Property>(new Enum(name, desc, enum_vals, getter, setter));
 }
 

pv/data/decode/decoder.cpp

@@ -28,9 +28,7 @@
 #include <pv/data/decodesignal.hpp>
 
 using pv::data::DecodeChannel;
-using std::set;
 using std::map;
-using std::shared_ptr;
 using std::string;
 
 namespace pv {

pv/data/decode/decoder.hpp

@@ -28,8 +28,6 @@
 #include <glib.h>
 
 using std::map;
-using std::set;
-using std::shared_ptr;
 using std::string;
 using std::vector;
 

pv/data/decodesignal.hpp

@@ -40,7 +40,6 @@ using std::condition_variable;
 using std::map;
 using std::mutex;
 using std::pair;
-using std::unordered_set;
 using std::vector;
 using std::shared_ptr;
 

pv/devicemanager.cpp

@@ -48,8 +48,6 @@ using std::string;
 using std::unique_ptr;
 using std::vector;
 
-using Glib::ustring;
-using Glib::Variant;
 using Glib::VariantBase;
 
 using sigrok::ConfigKey;

pv/mainwindow.cpp

@@ -53,7 +53,6 @@
 using std::bind;
 using std::dynamic_pointer_cast;
 using std::make_shared;
-using std::map;
 using std::placeholders::_1;
 using std::shared_ptr;
 using std::string;

pv/views/trace/cursor.cpp

@@ -34,7 +34,7 @@
 #include <cstdio>
 #include <limits>
 
-using std::abs; // Force usage of std::abs() instead of C's abs().
+using std::abs; // NOLINT. Force usage of std::abs() instead of C's abs().
 using std::shared_ptr;
 
 namespace pv {

pv/views/trace/decodetrace.cpp

@@ -56,14 +56,11 @@ extern "C" {
 using std::all_of;
 using std::make_pair;
 using std::max;
-using std::map;
 using std::min;
 using std::out_of_range;
 using std::pair;
 using std::shared_ptr;
-using std::make_shared;
 using std::tie;
-using std::unordered_set;
 using std::vector;
 
 using pv::data::decode::Annotation;

pv/views/trace/decodetrace.hpp

@@ -60,7 +60,7 @@ class Annotation;
 class Decoder;
 class Row;
 }
-}
+}  // namespace data
 
 namespace widgets {
 class DecoderGroupBox;

pv/views/trace/view.cpp

@@ -73,7 +73,6 @@ using pv::util::Timestamp;
 using std::back_inserter;
 using std::copy_if;
 using std::count_if;
-using std::dynamic_pointer_cast;
 using std::inserter;
 using std::max;
 using std::make_pair;

pv/views/trace/viewport.cpp

@@ -37,7 +37,7 @@ using std::abs;
 using std::back_inserter;
 using std::copy;
 using std::dynamic_pointer_cast;
-using std::none_of; // Used in assert()s.
+using std::none_of; // NOLINT. Used in assert()s.
 using std::shared_ptr;
 using std::stable_sort;
 using std::vector;