Mbed Client - Set FLOAT resource value

Are there any examples out there of an mbed OS LWM2M client setting the value of a float resource (as opposed to an integer)? I’m trying to do it using M2MResourceInstance’s set_value as:

res->set_value((const uint8_t *)&_temperature,
(const uint32_t)sizeof(_temperature));

I’ve set up the dynamic resource with type M2MResourceInstance::FLOAT and _temperature is cast as a float.

When I read the resource value though the DS API I am seeing gibberish (�A). Anybody done this before?