libpEpDatatypes/README.md

# libpEpDatatypes – A C++ wrapper for the basic C datatypes defined by the pEpEngine.

## Resources
* Repository: https://gitea.pep.foundation/pEp.foundation/libpEpDatatypes/
* Change management: <TODO: JIRA link here>

## Requirements & Platforms
* License: GPL3
* C++ standard: C++11
* supported compilers: at least gcc and clang (both have to work)

* Build sytem: GNU Make – Platforms: Linux, macOS
** Target: static library libpEpDatatypes.a
* Windows and Android builds will be done separatly

## Design goals & principles

* implement move c'tor & operator for cheep moves
* _Qpen question_: deep copy / shallow copy (with ref couning?) / only explicit copy?
* always initialize all members. Better safe than sorry.
* Ownership of the member pointees: rule of thumb: "const" pointees are non-owned, non-const pointees are owned by the data structure. Exceptional cases are documented explicitly.

## Public API
* defined in `namespace pEp::DT` 
* header files are installed in `PREFIX/include/pEp/` and are used via `#include <pEp/filename.hh>` – (Also shared with libpEpAdapter!)
* the linked list datatypes implement the API of [`std::forward_list`](https://en.cppreference.com/w/cpp/container/forward_list)

### Example usage

The following API is the target we're heading to:

```
#include <pEp/Types.hh>
#include <pEp/Adapter.hh>

int main()
{
    pEp::Message msg = "From: Alice Cooper <alice@mail.com>\n"
                       "To: Bob Smith <bob@mail.com>\n"
                       "Subject: Meeting\n"
                       "\n"
                       "Dear Bob,\n"
                       "\n"
                       "I will come.\n"
                       "\n"
                       "Alice.\n"_CRLF;

    try {
        auto enc = msg.encrypt();
        enc.send();
    }
    catch (pEp::err& e)
    {
    }

    return 0;
}
```

As an intermediate step the p≡p API in the engine must be fully
supported:

```
#include <pEp/message_api.h> // from pEpEngine
#include <pEp/Types.hh>      // from libpEpDatatypes
#include <pEp/Adapter.hh>    // from libpEpDatatypes

int main()
{
    pEp::Message msg_plain =
            "From: Alice Cooper <alice@mail.com>\nTo: Bob "
            "Smith <bob@mail.com>\nSubject: Meeting\n\n"
            "Dear Bob,\n\nI will come.\n\nAlice."_CRLF;
     
    ::message* msg_enc = nullptr;
    PEP_STATUS status = encrypt_message(msg_plain, enc_enc, ...);
    pEp::Message msg{std::move(msg_enc)}; // ownership of the pointee goes to 'msg'
    
    return 0;
}
```


## Implementation details
* Code-formatting: clang-format. Please try and use .clang-format from libpEpAdapter
* Include guards: #ifdef/#define style (not #pragma once), naming style: `LIBPEPDATATYPES_FILENAME_HH`