[std] Remove 'should' and 'may' from footnotes.

Partially addresses ISO/CS 017 (C++20 DIS)

Author: jensmaurer

source/algorithms.tex

@@ -4462,7 +4462,7 @@
 Copies elements in the range \range{first}{last}
 into the range \range{result - $N$}{result}
 starting from \tcode{last - 1} and proceeding to \tcode{first}.%
-\footnote{\tcode{copy_backward} should be used instead of copy
+\footnote{\tcode{copy_backward} can be used instead of copy
 when \tcode{last} is in the range \range{result - $N$}{result}.}
 For each positive integer $n \le N$,
 performs \tcode{*(result - $n$) = *(last - $n$)}.
@@ -4613,7 +4613,7 @@
 Moves elements in the range \range{first}{last}
 into the range \range{result - $N$}{result}
 starting from \tcode{last - 1} and proceeding to \tcode{first}.%
-\footnote{\tcode{move_backward} should be used instead of move
+\footnote{\tcode{move_backward} can be used instead of move
 when \tcode{last} is in the range \range{result - $N$}{result}.}
 For each positive integer $n \le N$,
 performs \tcode{*(result - $n$) = $E$}.

source/expressions.tex

@@ -3932,7 +3932,7 @@
 \pnum
 An object pointer
 can be explicitly converted to an object pointer of a different type.\footnote{The
-types may have different \cv-qualifiers, subject to
+types can have different \cv-qualifiers, subject to
 the overall
 restriction that a \tcode{reinterpret_cast} cannot cast away constness.}
 When a prvalue \tcode{v} of object pointer type is converted to
@@ -3970,7 +3970,7 @@
 A prvalue of type ``pointer to member of \tcode{X} of type \tcode{T1}''
 can be explicitly converted to a prvalue of a different type ``pointer to member of
 \tcode{Y} of type \tcode{T2}'' if \tcode{T1} and \tcode{T2} are both
-function types or both object types.\footnote{\tcode{T1} and \tcode{T2} may have
+function types or both object types.\footnote{\tcode{T1} and \tcode{T2} can have
 different \cv-qualifiers, subject to
 the overall restriction that a \tcode{reinterpret_cast} cannot cast away
 constness.} The null member pointer value\iref{conv.mem} is converted to the
@@ -5171,7 +5171,7 @@
 
 \pnum
 \indextext{\idxcode{new}!exception and}%
-If any part of the object initialization described above\footnote{This may
+If any part of the object initialization described above\footnote{This might
 include evaluating a \grammarterm{new-initializer} and/or calling
 a constructor.}
 terminates by throwing an exception and a suitable deallocation function
@@ -7351,12 +7351,12 @@
 
 \item
 an immediate subexpression of a \grammarterm{braced-init-list},%
-\footnote{Constant evaluation may be necessary to determine whether a narrowing conversion is performed\iref{dcl.init.list}.}
+\footnote{Constant evaluation might be necessary to determine whether a narrowing conversion is performed\iref{dcl.init.list}.}
 
 \item
 an expression of the form \tcode{\&} \grammarterm{cast-expression}
 that occurs within a templated entity,%
-\footnote{Constant evaluation may be necessary to determine whether such an expression is value-dependent\iref{temp.dep.constexpr}.}
+\footnote{Constant evaluation might be necessary to determine whether such an expression is value-dependent\iref{temp.dep.constexpr}.}
 or
 
 \item

source/future.tex

@@ -865,8 +865,6 @@
 How many additional write positions are made
 available is otherwise unspecified.%
 \indextext{unspecified}%
-\footnote{An implementation should consider \tcode{alsize} in making this
-decision.}
 If \tcode{palloc} is not a null pointer, the function calls
 \tcode{(*palloc)(n)}
 to allocate the new dynamic array object.
@@ -890,6 +888,11 @@
 or if
 \tcode{(strmode \& frozen) != 0},
 the function cannot extend the array (reallocate it with greater length) to make a write position available.
+
+\pnum
+\recommended
+An implementation should consider \tcode{alsize} in making the
+decision how many additional write positions to make available.}
 \end{itemdescr}
 
 \indexlibrarymember{pbackfail}{strstreambuf}%

source/iostreams.tex

@@ -430,8 +430,12 @@
 The objects are constructed and the associations are established at some
 time prior to or during the first time an object of class
 \tcode{ios_base::Init} is constructed, and in any case before the body
-of \tcode{main}\iref{basic.start.main} begins execution.\footnote{If it is possible for them to do so, implementations should
-initialize the objects earlier than required.}
+of \tcode{main}\iref{basic.start.main} begins execution.
+
+\recommended
+If it is possible for them to do so, implementations should
+initialize the objects earlier than required.
+
 The objects are not destroyed during program execution.\footnote{Constructors and destructors for objects with
 static storage duration can
 access these objects to read input from

source/locales.tex

@@ -4057,15 +4057,15 @@
 interpreted identically as the format specifiers in the string
 argument to the standard library function
 \indexlibraryglobal{strftime}%
-\tcode{strftime()}\footnote{Interpretation of the \tcode{modifier}
-argument is implementation-defined, but should follow POSIX
-conventions.},
+\tcode{strftime()},
 except that the sequence of characters produced for those specifiers
 that are described as depending on the C locale are instead \impldef{formatted character
 sequence generated by \tcode{time_put::do_put} in C
-locale}.\footnote{Implementations should refer to other standards
-such as POSIX
-for these definitions.}
+locale}.
+\begin{note}
+Interpretation of the \tcode{modifier}
+argument is implementation-defined.
+\end{note}
 
 \pnum
 \returns
@@ -4075,6 +4075,13 @@
 formats or by derivations. A space character is a reasonable
 default for this argument.
 \end{note}
+
+\pnum
+\recommended
+Interpretation of the \tcode{modifier} should follow POSIX conventions.
+Implementations should refer to other standards such as POSIX
+for a specification of the character sequences produced for
+those specifiers described as depending on the C locale.
 \end{itemdescr}
 
 \rSec3[locale.time.put.byname]{Class template \tcode{time_put_byname}}