Imported from /home/lorry/working-area/delta_boost-tarball/boost_1_54_0.tar.bz2.boost_1_54_0baserock/morph

1 files changed, 39 insertions, 0 deletions

diff --git a/libs/local_function/example/expensive_copy_cxx11_lambda.cpp b/libs/local_function/example/expensive_copy_cxx11_lambda.cpp
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--- /dev/null
+++ b/libs/local_function/example/expensive_copy_cxx11_lambda.cpp
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+
+// Copyright (C) 2009-2012 Lorenzo Caminiti
+// Distributed under the Boost Software License, Version 1.0
+// (see accompanying file LICENSE_1_0.txt or a copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+// Home at http://www.boost.org/libs/local_function
+
+#include <boost/config.hpp>
+#ifdef BOOST_NO_CXX11_LAMBDAS
+#   error "lambda functions required"
+#else
+
+#include <iostream>
+#include <cassert>
+
+//[expensive_copy_cxx11_lambda
+struct n {
+    int i;
+    n(int _i): i(_i) {}
+    n(n const& x): i(x.i) { // Some time consuming copy operation.
+        for (unsigned i = 0; i < 10000; ++i) std::cout << '.';
+    }
+};
+
+
+int main(void) {
+    n x(-1);
+
+    auto f = [x]() {        // Problem: Expensive copy, but if bind
+        assert(x.i == -1);  // by `&x` then `x` is not constant.
+    };
+    f();
+
+    return 0;
+}
+//]
+
+#endif // NO_LAMBDAS
+