License
Warranty and License
General
About the MWX Library
The MWX Library is designed to make programming for TWELITE modules easier and more extensible.
Based on the TWENET C Library previously used in MWSDK, the MWX Library serves as the application development layer.
+-----------------------+
| act (USER APPs)... |
+-----------------------+
| MWX C++ LIB |
+---------------+ |
| TWENET C LIB | |
+------------+----------+
| MAC LAYER | AHI APIs |
+-----------------------+
| TWELITE HARDWARE |
+-----------------------+
The name of the MWX library is Mono Wireless C++ Library for TWELITE. “MW” comes from MonoWireless, and “C++” → “CXX” → double X → “WX”. By overlapping this MW and WX, it became MWX. Code written using this library is called “act”.
Notations
This section describes the notations used in this explanation.
auto&&
Called a universal reference, it is often used in the standard library. In this library as well, auto&& is used in most cases.
auto in C language is a keyword used to declare local variables (automatic variables), but here it means declaration by type inference. In C++ template syntax, type names often become very complicated, and it is convenient when you can implement without explicitly specifying the type name.
The example below uses the standard library algorithm std::minmax_element to find the minimum and maximum values of the type of v, and the return value is declared with auto. In this case, the type inferred by auto is std::pair<int, int>.
#include <algorithm>
int v[] = { 1, 3, -1, 5, 10 };
auto&& result = std::minmax_element(std::begin(v), std::end(v));
Serial << "min=" << int(result.first)
<< ",max=" << int(result.second);
You need to refer to specialized books for the strict meaning of && in auto &&, but here, think of it as “whether the return is a reference type (similar to pointer passing in C) or a value, you can declare it without worrying.”
About namespaces
namespace, inline namespace, and using are used to redefine names. Some parts are omitted even in the explanation.
Limitations (TWENET)
The MWX library is not developed with the purpose of supporting all the underlying libraries and functions (functions in the TWENET C library, microcontroller peripheral functions provided by semiconductor vendors, IEEE802.15.4 functions).
Limitations (Use of C++)
The MWX library is written in C++ and the act is also written in C++. However, not all features of C++ can be used. Please note the following points especially.
- Memory allocation with
newandnew[]operators is possible, but the allocated memory cannot be freed. Most dynamic memory allocations in C++ libraries are practically unusable. - Constructors of global objects are not called.
- Note: If necessary, you can initialize including constructor calls by initializing in the setup function (
setup()) likenew ((void*)&obj_global) class_foo();. - Exceptions (
exception) cannot be used. - Virtual functions (
virtual) cannot be used. - Due to the above restrictions, only part of the C++ standard library such as STL can be used.
※ This is based on what we are aware of.
We have not conducted comprehensive verification of availability of the standard library or potentially usable parts. If any operational issues are found, please implement by other means.
About the Library Source Code
The source code can be referenced from the following.
{MWSDK installation folder}/TWENET/current/src/mwx- https://github.com/monowireless/mwx