Here we describe how Crubit bindings work with C++ special member functions and operator overloading (e.g. the copy constructor, or operator==) and with traits from the Rust standard library (e.g. the Clone or PartialEq traits).
Rust traits which return Self by value (or use mutable references) are only implemented in the bindings for a given C++ type if that type is is Unpin.
The following special member functions and traits are mapped bidirectionally:
| C++ | Rust | Notes |
|---|---|---|
| Default constructor | Default | |
| Trivial copy constructor | Copy | Rust bindings for C++ require that |
| : : : the C++ type is non-abstract and has : | ||
| : : : a public, trivial copy constructor : | ||
| : : : and destructor. : |
If the C++ type is Unpin, then the C++ special member functions below are mapped one-way into the corresponding Rust traits as follows:
| C++ API | Rust bindings | Notes |
|---|---|---|
| Custom copy constructor | Clone | TODO(b/259741191): Provide |
| : : : bidirectional map. : | ||
| Destructor | Drop | TODO(b/258251148): Provide |
| : : : bidirectional map. : | ||
| Constructor taking single | From<T> | Regardless if the constructor is |
: parameter of type T : : explicit in the C++ API or not : |
The C++ binary operators below are mapped one-way into the corresponding Rust traits as follows:
| C++ API | Rust bindings |
|---|---|
operator== | PartialEq |
operator< | PartialOrd |
operator+ | Add |
operator- | Sub |
operator* | Mul |
operator/ | Div |
operator% | Rem |
operator& | BitAnd |
operator| | BitOr |
operator^ | BitXor |
operator<< | Shl |
operator>> | Shr |
operator+= | AddAssign |
operator-= | SubAssign |
operator*= | MulAssign |
operator/= | DivAssign |
operator%= | RemAssign |
operator&= | BitAndAssign |
operator|= | BitOrAssign |
operator^= | BitXorAssign |
operator<<= | ShlAssign |
operator>>= | ShrAssign |
The C++ unary operators below are mapped one-way into the corresponding Rust traits as follows:
| C++ API | Rust bindings |
|---|---|
operator- | Neg |
operator! | Not |