add Set Map Template programs

01-Templet/21-SetMapTemplet/Makefile

+CC := g++ 
+ 
+#注意每行后面不要有空格，否则会算到目录名里面，导致问题
+SRC_DIR = ./
+BUILD_DIR = tmp
+OBJ_DIR = $(BUILD_DIR)/obj
+DEPS_DIR  = $(BUILD_DIR)/deps
+ 
+#这里添加其他头文件路径
+INC_DIR = \
+	-I./include \
+	-I./src \
+	
+#这里添加编译参数
+CC_FLAGS := $(INC_DIR) -g -std=c++17
+LNK_FLAGS := \
+	-L/usr/local/lib 
+ 
+#这里递归遍历3级子目录
+DIRS := $(shell find $(SRC_DIR) -maxdepth 3 -type d)
+ 
+#将每个子目录添加到搜索路径
+VPATH = $(DIRS)
+ 
+#查找src_dir下面包含子目录的所有cpp文件
+#SOURCES   = $(foreach dir, $(DIRS), $(wildcard $(dir)/*.cpp))  
+SOURCES   = SdoTst.cpp
+OBJS   = $(addprefix $(OBJ_DIR)/,$(patsubst %.cpp,%.o,$(notdir $(SOURCES))))  
+DEPS  = $(addprefix $(DEPS_DIR)/, $(patsubst %.cpp,%.d,$(notdir $(SOURCES))))  
+TARGET := $(patsubst %.cpp, %, $(SOURCES))
+
+
+$(TARGET):$(OBJS)
+	$(CC) $^ $(LNK_FLAGS) -o $@
+#编译之前要创建OBJ目录，确保目录存在
+$(OBJ_DIR)/%.o:%.cpp
+	if [ ! -d $(OBJ_DIR) ]; then mkdir -p $(OBJ_DIR); fi;\
+	$(CC) -c $(CC_FLAGS) -o $@ $<
+#编译之前要创建DEPS目录，确保目录存在
+#前面加@表示隐藏命令的执行打印
+$(DEPS_DIR)/%.d:%.cpp
+	@if [ ! -d $(DEPS_DIR) ]; then mkdir -p $(DEPS_DIR); fi;\
+	set -e; rm -f $@;\
+	$(CC) -MM $(CC_FLAGS) $< > $@.$$$$;\
+	sed 's,\($*\)\.o[ :]*,$(OBJ_DIR)/\1.o $@ : ,g' < $@.$$$$ > $@;\
+	rm -f $@.$$$$
+#前面加-表示忽略错误
+-include $(DEPS)
+.PHONY : clean
+clean:
+	rm -rf $(BUILD_DIR) $(TARGET)

01-Templet/21-SetMapTemplet/Sdo.h

+/* DataList - template parameter should be like x0, x1, x2, x3...
+ *  compare v against each x, to check if list contains or not contains v
+ *
+ * Usage:
+ *  using DL = DataList<3, 6, 8, 19>;
+ *  auto contains = DL::Contains(3); // contains = true
+ *  auto contains = DL::Contains(4); // contains = flase
+ */
+constexpr size_t MAX_DATA_LIST = 32;
+template<auto... vs>
+struct DataList {
+    static_assert(sizeof...(vs) <= MAX_DATA_LIST, "DataList too much, use std::set instead");
+    template<typename T>
+    constexpr static bool Contains(T val)
+    {
+        return ((val == vs) || ...);
+    }
+
+    template<typename T>
+    constexpr static bool NotContains(T val)
+    {
+        return !Contains(val);
+    }
+};
+
+/* DataPairs - template parameter should be like x0, y0, x1, y1, x2, y2, ..., z
+ *  if v matches one of x, return corresponding y, else return z as default
+ *
+ * Usage:
+ *  using DP = DataPairs<1, 10, 2, 20, 0>;
+ *  auto v = DP::ValueOf(1); // v == 10
+ *  auto w = DP::ValueOf(3); // w == 0
+ */
+constexpr size_t MAX_DATA_PAIRS = 16;
+template<auto x, auto y, auto z, auto... vs>
+struct DataPairs {
+    static_assert(sizeof...(vs) %2 == 0, "DataPairs must be odd, and >= 3");
+    static_assert(sizeof...(vs) < MAX_DATA_PAIRS * 2, "DataPairs too much, use std::map instead");
+
+    template<typename T>
+    constexpr static auto ValueOf(T val)
+    {
+        if constexpr (sizeof...(vs) == 0) {
+            return val == x ? y : z;
+        } else {
+            return val == x ? y : DataPairs<z, vs...>::ValueOf(val);
+        }
+    }
+};

01-Templet/21-SetMapTemplet/SdoTst.cpp

+#include <iostream>
+#include "Sdo.h"
+
+using namespace std;
+using DL = DataList<3, 6, 8, 19>;
+using DP = DataPairs<1, 10, 2, 20, 0>;
+
+int main()
+{
+    auto containsIs1 = DL::Contains(3); // contains = true
+    auto containsIs2 = DL::Contains(4); // contains = flase
+    cout << containsIs1 << endl;
+    cout << containsIs2 << endl;
+
+    auto v = DP::ValueOf(1); // v == 10
+    cout << "v = " << v << endl;
+    auto w = DP::ValueOf(3); // w == 0
+    cout << "w = " << w << endl;
+    auto x = DP::ValueOf(2); // x == 20
+    cout << "x = " << x << endl;
+
+    return 0;
+}
+