While working on this PR https://github.com/bitcoin/bitcoin/pull/18570 I ran into a bit confusing situation where in one function a **CWallet reference** was expected while two others dealt with **CWallet pointers**. My initial reaction was: `let's harmonize them by making them references`. However, not being part of the PR itself I did't change anything and completed the PR first.

Now, after having analyzed the `rpcwallet.cpp` code I came to the conclusion that:

* converting them all into references is not the solution as they're originally **shared_ptr**s
* but also: there is no (visible) reason why every RPC function should begin like this:

```cpp
std::shared_ptr<CWallet> const pwallet = GetWalletForJSONRPCRequest(request);
const CWallet* const pwallet = wallet.get();
```

This clearly defeats the purpose of shared pointers for no obvious reason. *Maybe I am missing something?*

In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept their original names (that is, *pwallet*). In the end, they're pointers too, so the most of the original code remained untouched.

However, some of the helper functions couldn't be changed because external code is accessing them and I didn't want to make this task "virulent". So I introduced new ("Ref") variants that expect **shared_ptr** parameters, namely: 

```cpp
void EnsureWalletRefIsUnlocked(const std::shared_ptr<CWallet>);
bool EnsureWalletRefIsAvailable(const std::shared_ptr<CWallet>, bool avoidException);
```

I have tested the code, with python and boost-tests, and could not find any errors. 
But before opening a PR I would like to open a discussion about this. 

Is there any reason to keep on working with raw pointers when every function call actually begins with *shared_ptr*s?

Regards,
"That is, each address can only appear once and there can only be one 'data' object.\n"
                    "For convenience, a dictionary, which holds the key-value pairs directly, is also accepted.",
                {
                    {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "",
                        {
                            {"address", RPCArg::Type::AMOUNT, RPCArg::Optional::NO, "A key-value pair. The key (string) is the bitcoin address, the value (float or string) is the amount in " + CURRENCY_UNIT + ""},
                        },
                        },
                    {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "",
                        {
                            {"data", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "A key-value pair. The key must be \"data\", the value is hex-encoded data"},
                        },
                    },
                },
            },
            {"conf_target", RPCArg::Type::NUM,  "wallet -txconfirmtarget", "Confirmation target in blocks"},
            {"estimate_mode", RPCArg::Type::STR,  "unset", std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
                        "       \"" + FeeModes("\"\n\"") + "\""},
            {"fee_rate", RPCArg::Type::AMOUNT,  "not set, fall back to wallet fee estimation", "Specify a fee rate in " + CURRENCY_ATOM + "/vB."},
            {"options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "",
                {
                    {"add_inputs", RPCArg::Type::BOOL,  "false", "If inputs are specified, automatically include more if they are not enough."},
                    {"add_to_wallet", RPCArg::Type::BOOL,  "true", "When false, returns a serialized transaction which will not be added to the wallet or broadcast"},
                    {"change_address", RPCArg::Type::STR_HEX,  "pool address", "The bitcoin address to receive the change"},
                    {"change_position", RPCArg::Type::NUM,  "random", "The index of the change output"},
                    {"change_type", RPCArg::Type::STR,  "set by -changetype", "The output type to use. Only valid if change_address is not specified. Options are \"legacy\", \"p2sh-segwit\", and \"bech32\"."},
                    {"conf_target", RPCArg::Type::NUM,  "wallet -txconfirmtarget", "Confirmation target in blocks"},
                    {"estimate_mode", RPCArg::Type::STR,  "unset", std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
            "       \"" + FeeModes("\"\n\"") + "\""},
                    {"fee_rate", RPCArg::Type::AMOUNT,  "not set, fall back to wallet fee estimation", "Specify a fee rate in " + CURRENCY_ATOM + "/vB."},