C/C++ compiler will compile your code if it is correct. Rust will not compile code if it can detect that it will not work or it is not safe even though the syntax is correct. It can guarantee the program is memory safe (double free, user after free, null dereferencing, using uninitialized memory, array bounds checks).

This makes large refactorings so much easier. It also makes working on large projects with lots of people much easier.