add Chapter08

Chapter08/template_function.cpp

@@ -0,0 +1,16 @@
+#include <cstdio> 
+
+template<typename T> 
+T add(T a, T b) { 
+   return a + b;  
+} 
+
+int main() { 
+    int result_int = add(1, 4); 
+    float result_float = add(1.11f, 1.91f); 
+
+    printf("result_int = %d\r\n", result_int); 
+    printf("result_float = %.2f\r\n", result_float); 
+    
+    return 0; 
+} 

Chapter08/template_function_point.cpp

@@ -0,0 +1,29 @@
+#include <cstdio>
+
+struct point { 
+    int x; 
+    int y; 
+
+    point operator+(const point& other) const { 
+        return point{x + other.x, y + other.y}; 
+    } 
+
+    void print() { 
+        printf("x = %d, y = %d\r\n", x, y); 
+    } 
+}; 
+
+template<typename T> 
+T add(T a, T b) { 
+   return a + b;  
+} 
+
+int main() {  
+
+    point a{1, 2}; 
+    point b{2, 1}; 
+
+    auto c = add(a, b); 
+    c.print();
+    return 0; 
+} 

Chapter08/template_specialization.cpp

@@ -0,0 +1,34 @@
+#include <cstdio>
+
+struct point { 
+    int x; 
+    int y; 
+
+    point operator+(const point& other) const { 
+        return point{x + other.x, y + other.y}; 
+    } 
+
+    void print() { 
+        printf("x = %d, y = %d\r\n", x, y); 
+    } 
+}; 
+
+template<typename T> 
+T add(T a, T b) { 
+   return a + b;  
+} 
+
+template<> 
+point add<point>(point a, point b) { 
+   return point{a.x+b.x+1, a.y+b.y+1}; 
+} 
+
+int main() {  
+
+    point a{1, 2}; 
+    point b{2, 1}; 
+
+    auto c = add(a, b); 
+    c.print();
+    return 0; 
+} 

Chapter08/tmpt_concepts.cpp

@@ -0,0 +1,44 @@
+#include <cstdio>
+#include <type_traits>
+
+struct point { 
+    int x; 
+    int y; 
+
+    point operator+(const point& other) const { 
+        return point{x + other.x, y + other.y}; 
+    } 
+
+    void print() { 
+        printf("x = %d, y = %d\r\n", x, y); 
+    } 
+}; 
+
+template<typename T> 
+concept Arithmetic = std::is_arithmetic_v<T>; 
+
+
+template<Arithmetic T> 
+T add(T a, T b) { 
+
+    T result = a + b; 
+    if constexpr (std::is_integral_v<T>) { 
+        printf("%d + %d = %d\r\n", a, b, result); 
+    } else if constexpr (std::is_floating_point_v<T>) { 
+        printf("%.2f + %.2f = %.2f\r\n", a, b, result); 
+    } 
+
+    return a + b;  
+} 
+
+int main() { 
+
+    auto a = add(1, 2); // OK 
+    auto b = add(1.1, 2.1); // OK 
+
+    point p_a{1, 2};  
+    point p_b{2, 1};   
+    auto c = add(p_a, p_b); // compile-error 
+
+    return 0; 
+} 

Chapter08/tmpt_crtp.cpp

@@ -0,0 +1,56 @@
+#include <span> 
+#include <cstdio> 
+#include <cstdint> 
+
+template<typename U> 
+class uart_interface { 
+public: 
+    void init(std::uint32_t baudrate = 9600) { 
+       static_cast<U*>(this)->initImpl(baudrate); 
+    } 
+
+    void write(std::span<const char> data) { 
+       static_cast<U*>(this)->writeImpl(data); 
+    } 
+}; 
+
+class uart_stm32 : public uart_interface<uart_stm32> { 
+public: 
+    void initImpl(std::uint32_t baudrate = 9600) { 
+        printf("uart_stm32::init: setting baudrate to %d\r\n", baudrate); 
+    } 
+
+    void writeImpl(std::span<const char> data) { 
+        printf("uart_stm32::write: "); 
+        for(auto ch: data) { 
+            putc(ch, stdout); 
+        } 
+    } 
+}; 
+
+template<typename T> 
+concept TheUart = std::derived_from<T, uart_interface<T>>; 
+
+template<TheUart T> 
+class gsm_lib{ 
+public: 
+    gsm_lib(T &u) : uart_(u) {} 
+
+    void init() {
+        printf("gsm_lib::init: sending AT command\r\n"); 
+        uart_.write("AT"); 
+    } 
+
+private: 
+    T &uart_; 
+}; 
+
+int main() { 
+    uart_stm32 uart_stm32_obj; 
+    uart_stm32_obj.init(115200); 
+
+    gsm_lib gsm(uart_stm32_obj); 
+    gsm.init(); 
+
+    return 0; 
+} 

Chapter08/tmpt_enable_if.cpp

@@ -0,0 +1,34 @@
+#include <cstdio>
+#include <type_traits>
+
+struct point { 
+    int x; 
+    int y; 
+
+    point operator+(const point& other) const { 
+        return point{x + other.x, y + other.y}; 
+    } 
+
+    void print() { 
+        printf("x = %d, y = %d\r\n", x, y); 
+    } 
+}; 
+
+template<typename T> 
+std::enable_if<std::is_arithmetic<T>::value, T>::type 
+add(T a, T b) { 
+   return a + b;  
+} 
+
+int main() { 
+
+    auto a = add(1, 2); // OK 
+    auto b = add(1.1, 2.1); // OK 
+
+    point p_a{1, 2};  
+    point p_b{2, 1};   
+    auto c = add(p_a, p_b); // compile-error 
+
+    return 0; 
+
+}