add template

.drone.yml

@@ -22,6 +22,7 @@ steps:
       - cd misc || exit
       - g++ sizeof.cpp -o sizeof && ./sizeof
       - g++ caching.cpp -o caching && ./caching
+      - g++ template.cpp -o template && ./template
       - echo "following program fails to show the effect of 'likely' due to CPU branch predictor."
       - g++ likely.cpp -o likely && ./likely
-      - cd -
+      - cd -

misc/template.cpp

@@ -0,0 +1,49 @@
+#include <assert.h>
+#include <iostream>
+#include <string>
+#include <vector>
+using namespace std;
+
+int32_t getInt() {
+    return INT32_MAX;
+}
+
+int64_t getInt64() {
+    return INT64_MAX;
+}
+
+void getStr(string& str) {
+    str = "abc";
+}
+void getVInt(vector<int>& vint) {
+    vint = {1, 2, 3};
+}
+void getVStr(vector<string>& vstr) {
+    vstr = {"abc", "def"};
+}
+
+template <typename T>
+T getVal() {
+    T val;
+    T& rVal = val;
+    if (typeid(T) == typeid(int)) {
+        (int&)rVal = getInt();
+    } else if (typeid(T) == typeid(int64_t)) {
+        (int64_t&)rVal = getInt64();
+    } else if (typeid(T) == typeid(string)) {
+        getStr((string&)rVal);
+    } else if (typeid(T) == typeid(vector<int>)) {
+        getVInt((vector<int>&)rVal);
+    } else if (typeid(T) == typeid(vector<string>)) {
+        getVStr((vector<string>&)rVal);
+    }
+    return val;
+}
+
+int main() {
+    assert(getVal<int32_t>() == INT32_MAX);
+    assert(getVal<int64_t>() == INT64_MAX);
+    assert(getVal<string>() == "abc");
+    assert(getVal<vector<int>>() == vector<int>({1, 2, 3}));
+    assert(getVal<vector<string>>() == vector<string>({"abc", "def"}));
+}