[libgpiod] [PATCH] bindings: cxx: remove superfluous std::move

[David Kozub <zub@xxxxxxxxxxxxxxxxxx>]

There is no need to use std::move on an r-value (e.g. std::move(gpiod::chip())).
Similarly, there is no need to use std::move for returning a local variable
as in:

T foo()
{
    U local;
    return std::move(local);
}

Not only it doesn't help, it actually inhibits named return value optimization.

See e.g. https://isocpp.org/blog/2013/02/no-really-moving-a-return-value-is-easy-stackoverflow

Signed-off-by: David Kozub <zub@xxxxxxxxxxxxxxxxxx>
---
 bindings/cxx/chip.cpp      | 16 ++++++++--------
 bindings/cxx/iter.cpp      |  8 ++++----
 bindings/cxx/line.cpp      |  8 ++++----
 bindings/cxx/line_bulk.cpp |  8 ++++----
 4 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/bindings/cxx/chip.cpp b/bindings/cxx/chip.cpp
index 9b825c7..54c85da 100644
--- a/bindings/cxx/chip.cpp
+++ b/bindings/cxx/chip.cpp
@@ -90,14 +90,14 @@ void chip::reset(void) noexcept
 {
 	this->throw_if_noref();
 
-	return ::std::move(::std::string(::gpiod_chip_name(this->_m_chip.get())));
+	return ::std::string(::gpiod_chip_name(this->_m_chip.get()));
 }
 
 ::std::string chip::label(void) const
 {
 	this->throw_if_noref();
 
-	return ::std::move(::std::string(::gpiod_chip_label(this->_m_chip.get())));
+	return ::std::string(::gpiod_chip_label(this->_m_chip.get()));
 }
 
 unsigned int chip::num_lines(void) const
@@ -119,7 +119,7 @@ line chip::get_line(unsigned int offset) const
 		throw ::std::system_error(errno, ::std::system_category(),
 					  "error getting GPIO line from chip");
 
-	return ::std::move(line(line_handle, *this));
+	return line(line_handle, *this);
 }
 
 line chip::find_line(const ::std::string& name) const
@@ -131,7 +131,7 @@ line chip::find_line(const ::std::string& name) const
 		throw ::std::system_error(errno, ::std::system_category(),
 					  "error looking up GPIO line by name");
 
-	return ::std::move(handle ? line(handle, *this) : line());
+	return handle ? line(handle, *this) : line();
 }
 
 line_bulk chip::get_lines(const ::std::vector<unsigned int>& offsets) const
@@ -141,7 +141,7 @@ line_bulk chip::get_lines(const ::std::vector<unsigned int>& offsets) const
 	for (auto& it: offsets)
 		lines.append(this->get_line(it));
 
-	return ::std::move(lines);
+	return lines;
 }
 
 line_bulk chip::get_all_lines(void) const
@@ -151,7 +151,7 @@ line_bulk chip::get_all_lines(void) const
 	for (unsigned int i = 0; i < this->num_lines(); i++)
 		lines.append(this->get_line(i));
 
-	return ::std::move(lines);
+	return lines;
 }
 
 line_bulk chip::find_lines(const ::std::vector<::std::string>& names) const
@@ -163,13 +163,13 @@ line_bulk chip::find_lines(const ::std::vector<::std::string>& names) const
 		line = this->find_line(it);
 		if (!line) {
 			lines.clear();
-			return ::std::move(lines);
+			return lines;
 		}
 
 		lines.append(line);
 	}
 
-	return ::std::move(lines);
+	return lines;
 }
 
 bool chip::operator==(const chip& rhs) const noexcept
diff --git a/bindings/cxx/iter.cpp b/bindings/cxx/iter.cpp
index 8c0b9ba..b1acc8c 100644
--- a/bindings/cxx/iter.cpp
+++ b/bindings/cxx/iter.cpp
@@ -43,7 +43,7 @@ chip_iter make_chip_iter(void)
 		throw ::std::system_error(errno, ::std::system_category(),
 					  "error creating GPIO chip iterator");
 
-	return ::std::move(chip_iter(iter));
+	return chip_iter(iter);
 }
 
 bool chip_iter::operator==(const chip_iter& rhs) const noexcept
@@ -62,7 +62,7 @@ chip_iter::chip_iter(::gpiod_chip_iter *iter)
 	::gpiod_chip* first = ::gpiod_chip_iter_next_noclose(this->_m_iter.get());
 
 	if (first != nullptr)
-		this->_m_current = ::std::move(chip(first));
+		this->_m_current = chip(first);
 }
 
 chip_iter& chip_iter::operator++(void)
@@ -91,7 +91,7 @@ chip_iter begin(chip_iter iter) noexcept
 
 chip_iter end(const chip_iter&) noexcept
 {
-	return ::std::move(chip_iter());
+	return chip_iter();
 }
 
 line_iter begin(line_iter iter) noexcept
@@ -101,7 +101,7 @@ line_iter begin(line_iter iter) noexcept
 
 line_iter end(const line_iter&) noexcept
 {
-	return ::std::move(line_iter());
+	return line_iter();
 }
 
 line_iter::line_iter(const chip& owner)
diff --git a/bindings/cxx/line.cpp b/bindings/cxx/line.cpp
index 470ed20..989976e 100644
--- a/bindings/cxx/line.cpp
+++ b/bindings/cxx/line.cpp
@@ -37,7 +37,7 @@ unsigned int line::offset(void) const
 
 	const char* name = ::gpiod_line_name(this->_m_line);
 
-	return ::std::move(name ? ::std::string(name) : ::std::string());
+	return name ? ::std::string(name) : ::std::string();
 }
 
 ::std::string line::consumer(void) const
@@ -46,7 +46,7 @@ unsigned int line::offset(void) const
 
 	const char* consumer = ::gpiod_line_consumer(this->_m_line);
 
-	return ::std::move(consumer ? ::std::string(consumer) : ::std::string());
+	return consumer ? ::std::string(consumer) : ::std::string();
 }
 
 int line::direction(void) const noexcept
@@ -173,7 +173,7 @@ line_event line::event_read(void) const
 
 	event.source = *this;
 
-	return ::std::move(event);
+	return event;
 }
 
 int line::event_get_fd(void) const
@@ -236,7 +236,7 @@ line find_line(const ::std::string& name)
 			break;
 	}
 
-	return ::std::move(ret);
+	return ret;
 }
 
 } /* namespace gpiod */
diff --git a/bindings/cxx/line_bulk.cpp b/bindings/cxx/line_bulk.cpp
index 3006b65..8369930 100644
--- a/bindings/cxx/line_bulk.cpp
+++ b/bindings/cxx/line_bulk.cpp
@@ -149,7 +149,7 @@ void line_bulk::release(void) const
 		throw ::std::system_error(errno, ::std::system_category(),
 					  "error reading GPIO line values");
 
-	return ::std::move(values);
+	return values;
 }
 
 void line_bulk::set_values(const ::std::vector<int>& values) const
@@ -197,7 +197,7 @@ line_bulk line_bulk::event_wait(const ::std::chrono::nanoseconds& timeout) const
 			ret.append(line(event_bulk.lines[i], this->_m_bulk[i].get_chip()));
 	}
 
-	return ::std::move(ret);
+	return ret;
 }
 
 line_bulk::operator bool(void) const noexcept
@@ -245,12 +245,12 @@ bool line_bulk::iterator::operator!=(const iterator& rhs) const noexcept
 
 line_bulk::iterator line_bulk::begin(void) noexcept
 {
-	return ::std::move(line_bulk::iterator(this->_m_bulk.begin()));
+	return line_bulk::iterator(this->_m_bulk.begin());
 }
 
 line_bulk::iterator line_bulk::end(void) noexcept
 {
-	return ::std::move(line_bulk::iterator(this->_m_bulk.end()));
+	return line_bulk::iterator(this->_m_bulk.end());
 }
 
 void line_bulk::throw_if_empty(void) const
-- 
2.20.1