Write-Only pointer type

Question

I\'m writing software for an embedded system.

We are using pointers to access registers of an FPGA device.
Some of the registers are read-only, while others are wr

Answer 1

I'd probably write a tiny wrapper class for each:

template 
class read_only {
    T volatile *addr;
public:
    read_only(int address) : addr((T *)address) {}
    operator T() volatile const { return *addr; }
};

template 
class write_only { 
    T volatile *addr;
public:
    write_only(int address) : addr ((T *)address) {}

    // chaining not allowed since it's write only.
    void operator=(T const &t) volatile { *addr = t; } 
};

At least assuming your system has a reasonable compiler, I'd expect both of these to be optimized so the generated code was indistinguishable from using a raw pointer. Usage:

read_only x(0x1234);
write_only y(0x1235);

y = x + 1;         // No problem

x = y;             // won't compile