Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/35525
[Changelog][Internal]
Adds ability to invoke an async JS callback from a C++ native module, as a task with priority.
This will allow native modules to schedule less important calls to JS thread with lower priority. One example use case is feeding collected perf metrics back to JS.
Reviewed By: javache
Differential Revision: D41492849
fbshipit-source-id: 12f738557972dc23398d9bb9a7a01125c79da070
Summary:
changelog: [internal]
You can read more about this rule on https://clang.llvm.org/extra/clang-tidy/checks/modernize-pass-by-value.html
# Isn't it wasteful to copy? Isn't reference more efficient?
This rule of thumb is no longer true since C++11 with move semantics. Let's look at some examples.
# Option one
```
class TextHolder
{
public:
TextBox(std::string const &text) : text_(text) {}
private:
std::string text_;
};
```
By using reference here, we prevent the caller from using rvalue to and avoiding copy. Regardless of what the caller passes in, copy always happens.
# Option two
```
class TextHolder
{
public:
TextBox(std::string const &text) : text_(text) {}
TextBox(std::string &&text) : text_(std::move(text)) {}
private:
std::string text_;
};
```
Here, we provide two constructors, one for const reference and one for rvalue reference. This gives the caller option to avoid copy. But now we have two constructors, which is not ideal.
# Option three (what we do in this diff)
```
class TextHolder
{
public:
TextBox(std::string text) : text_(std::move(text)) {}
private:
std::string text_;
};
```
Here, the caller has option to avoid copy and we only have single constructor.
Reviewed By: fkgozali, JoshuaGross
Differential Revision: D33276841
fbshipit-source-id: 619d5123d2e28937b22874650366629f24f20a63