Only thing I can think of is to make a reference variable to the inside struct.
typedef struct ControllerStruct_t{
uint16_t checkBytes;
uint16_t buttonState;
uint8_t leftTrigger;
uint8_t rightTrigger;
int16_t leftHatX;
int16_t leftHatY;
int16_t rightHatX;
int16_t rightHatY;
};
union ControllerUnion {
uint8_t rawBuffer[14];
ControllerStruct_t values;
} controller;
ControllerStruct_t &conValues = controller.values;
My question would be why you embed the struct in a union? Copying a struct can be done with memcpy and byte pointers.
Delta_G:
But I want to be able to load that buffer with a single memory copy and then get the values at will without having to do any extra bitmath
septillion:
...
I guess that is directed at my reply. I edited my reply before you posted the new one 
Something in the line of
struct MYSTRUCT
{
...
...
};
MYSTRUCT s1;
MYSTRUCT s2;
// copy s1 to s2
memcpy((byte*)&S2, (byte*)&S1, sizeof(MYSRUCT));
And reading the man page for memcpy, the cast is not even needed.
How about using a zero sized byte array as first member of the struct?
struct Controller {
uint8_t rawBuffer[0];
uint16_t checkBytes;
uint16_t buttonState;
uint8_t leftTrigger;
uint8_t rightTrigger;
int16_t leftHatX;
int16_t leftHatY;
int16_t rightHatX;
int16_t rightHatY;
} values;
Instead of sizeof(rawBuffer) you obviously should use sizeof(Controller)...
You can use an anonymous struct:
union ControllerUnion {
uint8_t rawBuffer[14];
struct {
...
};
};
This is standard C11, and GCC supports this as an extension for C++ and older C versions.
@sterretje, it's not about copying the struct as a whole but being able to dump a 14 bytes array of raw data in and read it back as separate variables.
I think oqibidipo nailed it, forgot you could do that. And Whandall as well although I would have never thought the compiler would allow me to me an array with size 0 
But now I think about it, you could also treat it as a uint8_t array. Skip the union (and make controller only the struct) and do ((uint8_t*)&controller)[8] = 33. But I think the solutions of oqibidipo and Whandall are far prettier
Delta_G:
The syntax for this is bulky though, I have to use 2 dots.
Meh. So what? Use a #define
#define foov foo.values
struct Controller foo;
septillion:
@sterretje, it's not about copying the struct as a whole but being able to dump a 14 bytes array of raw data in and read it back as separate variables.
I still don't get it. Make S1 an array of bytes and use memcpy. Or if this is e.g. a serial read, cast S2 to a byte pointer and read the data into the successive locations.
Yeah, if you can memcopy you can indeed, like I did, take the pointer of the struct. But if you want to fill it as an array the syntax gets ugly.
And yes, you could use a macro but
a) There are, as shown options without it which are safer so I would prefer them
b) It doesn't scale
@Delta_G, both options leave you with the same 
Although I'm still very surprised you're allowed to make zero size arrays 
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