The purpose of this data type is to generate C-compatible strings from Rust byte slices or vector arrays . Instances of this type are required to ensure that the byte data does not contain internal zero bytes ("nul characters") and the last byte is 0 ("nul terminator").
The relationship between CString and &CStr is like the relationship between albania whatsapp number data 5 million String and &str: CString and String own the string data themselves, while &CStr and &str just borrow the data.
1. Create a CString variable
CString can be created from a byte array slice or a vector byte array, or any other> any instance to create.
For example, you can create a CString directly from a String or a &str, since both implement this trait.
The CString::new method checks whether there is a zero (nul) byte in the provided &[u8] slice and returns an error if it finds one.
2. Output a raw pointer to a C string
CString implements the [as_ptr][CStr::as_ptr] method based on the Deref trait. This method gives a pointer of type *const c_char, which can be passed to an external function that can handle null-terminated strings, such as the strdup() function in C. If the C language code writes data to the memory known by the pointer, unpredictable results will occur because such a raw pointer accepted by the C language does not contain string length information.
