From 7739f628cbf8a4b9678c7562daa724a3426e0e6a Mon Sep 17 00:00:00 2001
From: Vitaliy Filippov <vitalif@yourcmc.ru>
Date: Wed, 13 Nov 2019 21:17:17 +0300
Subject: [PATCH] c++ lambda size test

---
 lambda_size.cpp | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 lambda_size.cpp

diff --git a/lambda_size.cpp b/lambda_size.cpp
new file mode 100644
index 00000000..1139d149
--- /dev/null
+++ b/lambda_size.cpp
@@ -0,0 +1,48 @@
+#include <iostream>
+#include <functional>
+#include <array>
+#include <cstdlib> // for malloc() and free()
+using namespace std;
+
+// replace operator new and delete to log allocations
+void* operator new(std::size_t n)
+{
+    cout << "Allocating " << n << " bytes" << endl;
+    return malloc(n);
+}
+
+void operator delete(void* p) throw()
+{
+    free(p);
+}
+
+class test
+{
+public:
+    std::string s;
+    void a(std::function<void()> & f, const char *str)
+    {
+        auto l = [this, str]() { cout << str << " ? " << s << " from this\n"; };
+        cout << "Assigning lambda3 of size " << sizeof(l) << endl;
+        f = l;
+    }
+};
+
+int main()
+{
+    std::array<char, 16> arr1;
+    auto lambda1 = [arr1](){};
+    cout << "Assigning lambda1 of size " << sizeof(lambda1) << endl;
+    std::function<void()> f1 = lambda1;
+
+    std::array<char, 17> arr2;
+    auto lambda2 = [arr2](){};
+    cout << "Assigning lambda2 of size " << sizeof(lambda2) << endl;
+    std::function<void()> f2 = lambda2;
+
+    test t;
+    std::function<void()> f3;
+    t.s = "str";
+    t.a(f3, "huyambda");
+    f3();
+}