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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 18:24:20 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 18:24:20 +0000
commit483eb2f56657e8e7f419ab1a4fab8dce9ade8609 (patch)
treee5d88d25d870d5dedacb6bbdbe2a966086a0a5cf /src/boost/libs/math/example/policy_ref_snip3.cpp
parentInitial commit. (diff)
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Adding upstream version 14.2.21.upstream/14.2.21upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/boost/libs/math/example/policy_ref_snip3.cpp')
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diff --git a/src/boost/libs/math/example/policy_ref_snip3.cpp b/src/boost/libs/math/example/policy_ref_snip3.cpp
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+// Copyright John Maddock 2007.
+// Copyright Paul A. Bristow 2010
+// Use, modification and distribution are subject to the
+// Boost Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// Note that this file contains quickbook mark-up as well as code
+// and comments, don't change any of the special comment mark-ups!
+
+double some_value = 2.;
+
+//[policy_ref_snip3
+
+#include <boost/math/special_functions/gamma.hpp>
+
+using namespace boost::math::policies;
+using boost::math::tgamma;
+
+// Define a new policy *not* internally promoting RealType to double:
+typedef policy<
+ promote_double<false>
+ > my_policy;
+
+// Call the function, applying the new policy:
+double t1 = tgamma(some_value, my_policy());
+
+// Alternatively we could use helper function make_policy,
+// and concisely define everything at the call site:
+double t2 = tgamma(some_value, make_policy(promote_double<false>()));
+
+//] //[\policy_ref_snip3]
+
+#include <iostream>
+using std::cout; using std::endl;
+
+int main()
+{
+ cout << "tgamma(some_value, my_policy()) = " << t1
+ << ", tgamma(some_value, make_policy(promote_double<false>()) = " << t2 << endl;
+}