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

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

Author: jensmaurer

source/algorithms.tex

@@ -4453,7 +4453,7 @@
 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 - $n$)}.
@@ -4604,7 +4604,7 @@
 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/basic.tex

@@ -1531,7 +1531,7 @@
 A name used in the definition of a class \tcode{X}%
 \footnote{This
 refers to unqualified names following the class name;
-such a name may be used in a \grammarterm{base-specifier} or
+such a name might be used in a \grammarterm{base-specifier} or
 in the \grammarterm{member-specification} of the class definition.}
 outside of a complete-class context\iref{class.mem} of \tcode{X}
 shall be declared in one of the following ways:

source/containers.tex

@@ -5844,7 +5844,7 @@
 \throws
 \tcode{length_error} if \tcode{n >
 max_size()}.\footnote{\tcode{reserve()} uses \tcode{Allocator::allocate()} which
-may throw an appropriate exception.}
+can throw an appropriate exception.}
 
 \pnum
 \complexity

source/declarations.tex

@@ -7598,7 +7598,7 @@
 An ambiguity exists if the best match finds two functions with the same
 signature, even if one is in a namespace reachable through
 \grammarterm{using-directive}{s} in the namespace of the other.\footnote{During
-name lookup in a class hierarchy, some ambiguities may be
+name lookup in a class hierarchy, some ambiguities can be
 resolved by considering whether one member hides the other along some
 paths\iref{class.member.lookup}. There is no such disambiguation when
 considering the set of names found as a result of following

source/expressions.tex

@@ -292,7 +292,7 @@
 whose type is not similar\iref{conv.qual} to
 one of the following types the behavior is
 undefined:\footnote{The intent of this list is to specify those circumstances in which an
-object may or may not be aliased.}
+object can or cannot be aliased.}
 \begin{itemize}
 \item the dynamic type of the object,
 
@@ -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
@@ -3972,7 +3972,7 @@
 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
@@ -4572,7 +4572,7 @@
 potentially-overlapping subobject is
 the size of the type, not the size of the subobject.%
 \footnote{The actual size of a potentially-overlapping subobject
-may be less than the result of
+can be less than the result of
 applying \tcode{sizeof} to the subobject, due to virtual base classes
 and less strict padding requirements on potentially-overlapping subobjects.}
 \indextext{array!\idxcode{sizeof}}%
@@ -5176,7 +5176,7 @@
 
 \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
@@ -7317,7 +7317,7 @@
 that is usable in constant expressions or
 has constant initialization\iref{basic.start.static}.%
 \footnote{Testing this condition
-may involve a trial evaluation of its initializer as described above.}
+might involve a trial evaluation of its initializer as described above.}
 \begin{example}
 \begin{codeblock}
 template<bool> struct X {};
@@ -7358,12 +7358,12 @@
 
 \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

@@ -431,6 +431,11 @@
 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.
+
+\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
@@ -3047,7 +3052,7 @@
 Initializes:\footnote{The default constructor is protected for class
 \tcode{basic_streambuf}
 to assure that only objects for classes
-derived from this class may be constructed.}
+derived from this class can be constructed.}
 \begin{itemize}
 \item
 all pointer member objects to null pointers,

source/iterators.tex

@@ -593,7 +593,7 @@
 that designate the beginning and end of the computation, or an iterator and a
 count that designate the beginning and the number of elements to which the
 computation is to be applied.\footnote{The sentinel denoting the end of a range
-may have the same type as the iterator denoting the beginning of the range, or a
+can have the same type as the iterator denoting the beginning of the range, or a
 different type.}
 
 \pnum

source/lex.tex

@@ -637,9 +637,9 @@
 specified in \tref{lex.name.disallowed}.
 Upper- and lower-case letters are
 different. All characters are significant.\footnote{On systems in which linkers cannot accept extended
-characters, an encoding of the \grammarterm{universal-character-name} may be used in
+characters, an encoding of the \grammarterm{universal-character-name} can be used in
 forming valid external identifiers. For example, some otherwise unused
-character or sequence of characters may be used to encode the
+character or sequence of characters can be used to encode the
 \tcode{\textbackslash u} in a \grammarterm{universal-character-name}. Extended
 characters may produce a long external identifier, but \Cpp{} does not
 place a translation limit on significant characters for external

source/lib-intro.tex

@@ -851,7 +851,7 @@
 or namespaces nested within namespace
 \tcode{std}.\footnote{The C standard library headers\iref{depr.c.headers} also define
 names within the global namespace, while the \Cpp{} headers for C library
-facilities\iref{headers} may also define names within the global namespace.}%
+facilities\iref{headers} can also define names within the global namespace.}%
 \indextext{namespace}
 It is unspecified whether names declared in a specific namespace are declared
 directly in that namespace or in an inline namespace inside that
@@ -2209,7 +2209,7 @@
 that meets the minimum requirements
 of this document.
 Therefore
-an implementation may elect,
+an implementation can elect,
 under the as-if rule\iref{intro.execution},
 to provide any customization point
 in the form
@@ -2775,7 +2775,7 @@
 described in \ref{\firstlibchapter} through \ref{\lastlibchapter} and
 \ref{depr} shall behave as if the implementation declared no additional
 non-member function signatures.\footnote{A valid \Cpp{} program always
-calls the expected library non-member function. An implementation may
+calls the expected library non-member function. An implementation can
 also define additional non-member functions that would otherwise not
 be called by a valid \Cpp{} program.}
 

source/locales.tex

@@ -2153,8 +2153,8 @@
 constant number of \tcode{externT} characters needed to produce an internal
 character; or \tcode{0} if this number is not a constant.\footnote{If \tcode{encoding()}
 yields \tcode{-1}, then more than \tcode{max_length()} \tcode{externT} elements
-may be consumed when producing a single \tcode{internT} character, and additional
-\tcode{externT} elements may appear at the end of a sequence after those that
+can be consumed when producing a single \tcode{internT} character, and additional
+\tcode{externT} elements can appear at the end of a sequence after those that
 yield the final \tcode{internT} character.}
 \end{itemdescr}
 
@@ -3749,7 +3749,7 @@
 An enumeration value indicating the preferred order of components for
 those date formats that are composed of day, month, and year.\footnote{This
 function is intended as a convenience only, for common
-formats, and may return
+formats, and can return
 \tcode{no_order}
 in valid locales.}
 Returns
@@ -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}}

source/modules.tex

@@ -526,7 +526,7 @@
 non-exported \grammarterm{module-import-declaration}{s}
 in the module unit purview of $U$.\footnote{This is consistent
 with the rules for visibility of imported names\iref{basic.scope.namespace}.}
-These rules may in turn lead to the importation of yet more
+These rules can in turn lead to the importation of yet more
 translation units.
 
 \pnum

source/numerics.tex

@@ -2316,7 +2316,7 @@
 \tcode{E(q)}%
 \indextext{constructor!random number engine requirement}\footnote{  This constructor
   (as well as the subsequent corresponding \tcode{seed()} function)
-  may be particularly useful
+  can be particularly useful
   to applications requiring
   a large number of independent random sequences.
   }
@@ -7125,7 +7125,7 @@
 that has zero length.\footnote{This default constructor is essential,
 since arrays of
 \tcode{valarray}
-may be useful.
+can be useful.
 After initialization, the length of an empty array can be increased with the
 \tcode{resize}
 member function.}
@@ -8176,7 +8176,7 @@
 Such a slice is specified by a starting index, a length, and a
 stride.\footnote{BLAS stands for
 \textit{Basic Linear Algebra Subprograms.}
-\Cpp{} programs may instantiate this class.
+\Cpp{} programs can instantiate this class.
 See, for example,
 Dongarra, Du Croz, Duff, and Hammerling:
 \textit{A set of Level 3 Basic Linear Algebra Subprograms};

source/overloading.tex

@@ -1233,7 +1233,7 @@
 is applied to the value returned, with the original second
 operand.\footnote{If the value returned by the
 \tcode{\keyword{operator}->}
-function has class type, this may result in selecting and calling another
+function has class type, this can result in selecting and calling another
 \tcode{\keyword{operator}->}
 function.
 The process repeats until an