add Chapter01 examples

Chapter01/bloat.cpp

@@ -0,0 +1,107 @@
+#include <array>
+#include <cstdio>
+
+#if USE_TEMPLATES
+template <class T, std::size_t N> struct ring_buffer {
+  std::array<T, N> arr;
+  std::size_t write_idx = 0; // Index of the next element to write (push)
+  std::size_t read_idx = 0;  // Index of the next element to read (pop)
+  std::size_t count = 0;     // Number of elements in the buffer
+
+  void push(T t) {
+    arr.at(write_idx) = t;
+    write_idx = (write_idx + 1) % N;
+    if (count < N) {
+      count++;
+    } else {
+      // buffer is full, move forward read_idx
+      read_idx = (read_idx + 1) % N;
+    }
+  }
+
+  T pop() {
+    if (count == 0) {
+      // Buffer is empty, return a default-constructed T.
+      return T{};
+    }
+    T value = arr.at(read_idx);
+    read_idx = (read_idx + 1) % N;
+    --count;
+    return value;
+  }
+
+  bool is_empty() const { return count == 0; }
+};
+
+#else
+
+#define N 10
+
+struct ring_buffer_int {
+  std::array<int, N> arr;
+  std::size_t write_idx = 0; // Index of the next element to write (push)
+  std::size_t read_idx = 0;  // Index of the next element to read (pop)
+  std::size_t count = 0;     // Number of elements in the buffer
+
+  void push(int t) {
+    arr.at(write_idx) = t;
+    write_idx = (write_idx + 1) % N;
+    ++count;
+  }
+
+  int pop() {
+    if (count == 0) {
+      // Buffer is empty, return a default-constructed T.
+      return int{};
+    }
+    int value = arr.at(read_idx);
+    read_idx = (read_idx + 1) % N;
+    --count;
+    return value;
+  }
+};
+
+struct ring_buffer_float {
+  std::array<float, N> arr;
+  std::size_t write_idx = 0; // Index of the next element to write (push)
+  std::size_t read_idx = 0;  // Index of the next element to read (pop)
+  std::size_t count = 0;     // Number of elements in the buffer
+
+  void push(float t) {
+    arr.at(write_idx) = t;
+    write_idx = (write_idx + 1) % N;
+    ++count;
+  }
+
+  float pop() {
+    if (count == 0) {
+      // Buffer is empty, return a default-constructed T.
+      return float{};
+    }
+    float value = arr.at(read_idx);
+    read_idx = (read_idx + 1) % N;
+    --count;
+    return value;
+  }
+};
+#endif
+
+int main() {
+#ifdef USE_TEMPLATES
+  ring_buffer<int, 10> buffer1;
+  ring_buffer<float, 10> buffer2;
+#else
+  ring_buffer_int buffer1;
+  ring_buffer_float buffer2;
+#endif
+  for (int i = 0; i < 20; i++) {
+    buffer1.push(i);
+    buffer2.push(i + 0.2f);
+  }
+
+  for (int i = 0; i < 10; i++) {
+    printf("%d, %.2f\r\n", buffer1.pop(), buffer2.pop());
+  }
+
+  return 0;
+}