Another shot at fixing the issues with (constant) struct literals and their addresses. See DMD2682, #218, #324. The idea is to separate the notion of const from 'this variable can always be replaced with its initializer' in the frontend. To do that, I introduced Declaration::isSameAsInitializer, which is overridden in VarDeclaration to return false for constants that have a struct literal initializer. So {{{ const S s = S(5); void foo() { auto ps = &s; } // is no longer replaced by void foo() { auto ps = &(S(5)); } }}} To make taking the address of a struct constant with a struct-initializer outside of function scope possible, I made sure that AddrExp::optimize doesn't try to run the argument's optimization with WANTinterpret - that'd again replace the constant with a struct literal temporary.

extern(C) int printf(char*, ...);

void main()
{
    printf("Pointer arithmetic test\n");
    int* p;
    printf("0x%x\n", p);
    assert(p++ is null);
    assert(cast(size_t)p == 4);
    printf("0x%x\n", p);
    p--;
    assert(p is null);
    printf("0x%x\n", p);
    int d = 4;
    p+=d;
    printf("0x%x\n", p);
    assert(cast(size_t)p == 16);
    d = 2;
    p+=d;
    printf("0x%x\n", p);
    assert(cast(size_t)p == 0x18);
    d = 6;
    p-=d;
    printf("0x%x\n", p);
    assert(p is null);
    printf("  SUCCESS\n");
}

void fill_byte_array(ubyte* a, size_t n, ubyte v)
{
    auto p = a;
    auto end = a+n;
    while (p !is end)
        *p++ = v;
}