Minor fixes from review [ci skip]

doc/background/special_tut.qbk

@@ -366,6 +366,9 @@ Now we just need to write the test driver program, at it's most basic it looks s
       //
    #ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
       test(0.1L, "long double");
+   #ifndef BOOST_MATH_NO_REAL_CONCEPT_TESTS
+      test(boost::math::concepts::real_concept(0.1), "real_concept);
+   #endif
    #else
       std::cout << "<note>The long double tests have been disabled on this platform "
          "either because the long double overloads of the usual math functions are "

doc/html/math_toolkit/lambert_w.html

@@ -1402,7 +1402,7 @@ if (f(w) / f'</span><span class="special">(</span><span class="identifier">w</sp
 </pre>
 <p>
       The arrays are as <code class="computeroutput"><span class="keyword">const</span></code> and <code class="computeroutput"><span class="keyword">constexpr</span></code> and <code class="computeroutput"><span class="keyword">static</span></code>
-      as possible (for the compiler version), using static constexpr macro.
+      as possible (for the compiler version), using static constexpr.
       (See <a href="../../../tools/lambert_w_lookup_table_generator.cpp" target="_top">lambert_w_lookup_table_generator.cpp</a>
       The precision was chosen to ensure that if used as <code class="computeroutput"><span class="keyword">long</span>
       <span class="keyword">double</span></code> arrays, then the values output

include/boost/math/quadrature/trapezoidal.hpp

@@ -17,6 +17,7 @@
 
 #include <cmath>
 #include <limits>
+#include <utility>
 #include <stdexcept>
 #include <boost/math/constants/constants.hpp>
 #include <boost/math/special_functions/fpclassify.hpp>
@@ -111,14 +112,9 @@ auto trapezoidal(F f, Real a, Real b, Real tol, std::size_t max_refinements, Rea
 
     return static_cast<K>(I1);
 }
-#if defined(_MSC_VER) && (_MSC_VER < 1800)
-// Template argument deduction failure otherwise:
-template<class F, class Real>
-auto trapezoidal(F f, Real a, Real b, Real tol = 0, std::size_t max_refinements = 12, Real* error_estimate = 0, Real* L1 = 0)->decltype(std::declval<F>()(std::declval<Real>()))
-#else
+
 template<class F, class Real>
 auto trapezoidal(F f, Real a, Real b, Real tol = boost::math::tools::root_epsilon<Real>(), std::size_t max_refinements = 12, Real* error_estimate = nullptr, Real* L1 = nullptr)->decltype(std::declval<F>()(std::declval<Real>()))
-#endif
 {
    return trapezoidal(f, a, b, tol, max_refinements, error_estimate, L1, boost::math::policies::policy<>());
 }