C++ guidelines.

- Removed casts.
- Removed macros.
- Const correctness.
- Using new/delete instead of realloc/free.
- Variable naming.
- Interface documentation.

docs/api/serialmux.rst

@@ -9,5 +9,8 @@ Serial multiplexer
 Class definition
 ----------------
 
-.. doxygenclass:: SerialMux
+.. doxygenclass:: SerialMux_
+   :members:
+
+.. doxygentypedef:: SerialMux
    :members:

src/buffer.tcc

@@ -2,113 +2,113 @@
 
 #include <Arduino.h>
 
-/*!
- * Ring buffer.
+/*! Ring buffer.
+ *
+ * \tparam bits Buffer size control (2^`bits`).
  */
 template <uint8_t bits>
 class Buffer {
-  public:
-    Buffer();
-
-    uint8_t available();
-    uint8_t read(uint8_t*, uint8_t);
-    int16_t read();
-    void write(uint8_t*, uint8_t);
-    void write(uint8_t);
-    int16_t peek();
-
-  private:
-    uint8_t _buffer[1ul << bits] = {};
-    uint8_t _start: bits;
-    uint8_t _end: bits;
-    uint8_t _mask = (1ul << bits) - 1;
+public:
+  /*! Create a ring buffer. */
+  Buffer();
+
+
+  /*! Get the number of bytes available for reading.
+   *
+   * \return Number of bytes.
+   */
+  uint8_t available() const;
+
+  /*! Read `size` bytes of data.
+   *
+   * \param[out] data Buffer to receive `size` bytes of data.
+   * \param[in] size Number of bytes to read.
+   *
+   * \return Number of bytes read.
+   */
+  uint8_t read(uint8_t* const, uint8_t const);
+
+  /*! Read one byte of data.
+   *
+   * \return The first byte of incoming data or `-1` if no data is available.
+   */
+  int16_t read();
+
+  /*! Write `size` bytes of data.
+   *
+   * \param[in] data Buffer containing `size` bytes of data.
+   * \param[in] size Number of bytes to write.
+   *
+   * \return Number of bytes written.
+   */
+  void write(uint8_t* const, uint8_t const);
+
+  /*! Write one byte of data.
+   *
+   * \param[in] data Data.
+   */
+  void write(uint8_t const);
+
+  /*! Return the next byte of incoming data without removing it from the
+   * buffer.
+   *
+   * \return The first byte of incoming data or `-1` if no data is available.
+   */
+  int16_t peek() const;
+
+private:
+  uint8_t buffer_[1ul << bits]{};
+  uint8_t start_: bits;
+  uint8_t end_: bits;
+  uint8_t mask_ = (1ul << bits) - 1;
 };
 
 
-/*!
- * Constructor.
- */
 template <uint8_t bits>
 Buffer<bits>::Buffer() {
-  _start = 0;
-  _end = 0;
+  start_ = 0;
+  end_ = 0;
 }
 
 
-/*!
- * Get the number of bytes available for reading.
- *
- * \return Number of bytes.
- */
 template <uint8_t bits>
-uint8_t Buffer<bits>::available() {
-  return (_end - _start) & _mask;
+uint8_t Buffer<bits>::available() const {
+  return (end_ - start_) & mask_;
 }
 
-/*!
- * Read `size` bytes of data.
- *
- * \param data Buffer to receive `size` bytes of data.
- * \param size Number of bytes to read.
- *
- * \return Number of bytes read.
- */
 template <uint8_t bits>
-uint8_t Buffer<bits>::read(uint8_t* data, uint8_t size) {
+uint8_t Buffer<bits>::read(uint8_t* const data, uint8_t const size) {
   uint8_t size_ = min(size, available());
   for (uint8_t i = 0; i < size_; i++) {
-    data[i] = _buffer[_start++];
+    data[i] = buffer_[start_++];
   }
   return size_;
 }
 
-/*!
- * Read one byte of data.
- *
- * \return The first byte of incoming data or `-1` if no data is available.
- */
 template <uint8_t bits>
 int16_t Buffer<bits>::read() {
-  if (_start != _end) {
-    return _buffer[_start++];
+  if (start_ != end_) {
+    return buffer_[start_++];
   }
   return -1;
 }
 
-/*!
- * Write `size` bytes of data.
- *
- * \param data Buffer containing `size` bytes of data.
- * \param size Number of bytes to write.
- *
- * \return Number of bytes written.
- */
 template <uint8_t bits>
-void Buffer<bits>::write(uint8_t* data, uint8_t size) {
+void Buffer<bits>::write(uint8_t* const data, uint8_t size) {
   for (uint8_t i = 0; i < size; i++) {
-    _buffer[_end++] = data[i];
+    buffer_[end_++] = data[i];
   }
 }
 
-/*!
- * Write one byte of data.
- *
- * \param data Data.
- */
 template <uint8_t bits>
 void Buffer<bits>::write(uint8_t data) {
-  _buffer[_end++] = data;
+  buffer_[end_++] = data;
 }
 
-/*!
- * Return the next byte of incoming data without removing it from the buffer.
- *
- * \return The first byte of incoming data or `-1` if no data is available.
- */
 template <uint8_t bits>
-int16_t Buffer<bits>::peek() {
-  if (_start != _end) {
-    return _buffer[_start];
+int16_t Buffer<bits>::peek() const {
+  if (start_ != end_) {
+    return buffer_[start_];
   }
   return -1;
 }

src/serialMux.h

@@ -1,6 +1,3 @@
 #pragma once
 
 #include "vSerial.tcc"
-
-#define SerialMux SerialMux<>
-#define VSerial VSerial<>