[{ex,in}clusive.scan] Reflow and use codeblocks

In pursuit of #693.

Author: tkoeppe

source/numerics.tex

@@ -9125,7 +9125,8 @@
 \pnum
 \effects Equivalent to:
 \begin{codeblock}
-return exclusive_scan(std::forward<ExecutionPolicy>(exec), first, last, result, init, plus<>());
+return exclusive_scan(std::forward<ExecutionPolicy>(exec),
+                      first, last, result, init, plus<>());
 \end{codeblock}
 \end{itemdescr}
 
@@ -9136,7 +9137,8 @@
   OutputIterator exclusive_scan(InputIterator first, InputIterator last,
                                 OutputIterator result,
                                 T init, BinaryOperation binary_op);
-template<class ExecutionPolicy, class InputIterator, class OutputIterator, class T, class BinaryOperation>
+template<class ExecutionPolicy,
+         class InputIterator, class OutputIterator, class T, class BinaryOperation>
   OutputIterator exclusive_scan(ExecutionPolicy&& exec,
                                 InputIterator first, InputIterator last,
                                 OutputIterator result,
@@ -9153,7 +9155,9 @@
 \pnum
 \effects
 Assigns through each iterator \tcode{i} in \range{result}{result + (last - first)} the value of
-\tcode{\textit{GENERALIZED_NONCOMMUTATIVE_SUM}(binary_op, init, *j, ...)}
+\begin{codeblock}
+@\placeholder{GENERALIZED_NONCOMMUTATIVE_SUM}@(binary_op, init, *j, ...)
+\end{codeblock}
 for every \tcode{j} in \range{first}{first + (i - result)}.
 
 \pnum
@@ -9226,7 +9230,8 @@
   OutputIterator inclusive_scan(InputIterator first, InputIterator last,
                                 OutputIterator result,
                                 BinaryOperation binary_op, T init);
-template<class ExecutionPolicy, class InputIterator, class OutputIterator, class BinaryOperation, class T>
+template<class ExecutionPolicy,
+         class InputIterator, class OutputIterator, class BinaryOperation, class T>
   OutputIterator inclusive_scan(ExecutionPolicy&& exec,
                                 InputIterator first, InputIterator last,
                                 OutputIterator result,