I am calling geth rpc method eth_getStorageAt using json-rpc-cpp libarary. I need to know the parameters' names for the method. I can find parameters' names for eth_sendTransaction from here, which includes "from", "to" and so on. My questions is where to find the similiar ones for eth_getStorageAt, thanks.
Have a look at the examples in that link. You don't need to create an object that includes the keys of the parameters' names.
eth_getStorageAt Returns the value from a storage position at a given address. Parameters * DATA, 20 Bytes - address of the storage. * QUANTITY - integer of the position in the storage. * QUANTITY|TAG - integer block number, or the string "latest", "earliest" or "pending", see the default block parameter Returns DATA - the value at this storage position.