# The needed includes for variants support.
m4_define([b4_variant_includes],
[b4_parse_assert_if([[#include <typeinfo>]])[
-#include <cstdlib> // abort
#ifndef YYASSERT
# include <cassert>
# define YYASSERT assert
, tname (YY_NULL)])[
{}
- /// Instantiate a \a T in here.
+ /// Construct and fill.
+ template <typename T>
+ variant (const T& t)]b4_parse_assert_if([
+ : built (true)
+ , tname (typeid (T).name ())])[
+ {
+ YYASSERT (sizeof (T) <= S);
+ new (buffer.raw) T (t);
+ }
+
+ /// Destruction, allowed only if empty.
+ ~variant ()
+ {]b4_parse_assert_if([
+ YYASSERT (!built);
+ ])[}
+
+ /// Instantiate an empty \a T in here.
template <typename T>
T&
build ()
{]b4_parse_assert_if([
- //YYASSERT (!built);
- //YYASSERT (!tname);
+ YYASSERT (!built);
+ YYASSERT (!tname);
YYASSERT (sizeof (T) <= S);
built = true;
tname = typeid (T).name ();])[
T&
build (const T& t)
{]b4_parse_assert_if([
- //YYASSERT (!built);
- //YYASSERT (!tname);
+ YYASSERT (!built);
+ YYASSERT (!tname);
YYASSERT (sizeof (T) <= S);
built = true;
tname = typeid (T).name ();])[
return *new (buffer.raw) T (t);
}
- /// Construct and fill.
- template <typename T>
- variant (const T& t)]b4_parse_assert_if([
- : built (true)
- , tname (typeid (T).name ())])[
- {
- YYASSERT (sizeof (T) <= S);
- new (buffer.raw) T (t);
- }
-
/// Accessor to a built \a T.
template <typename T>
T&
}
/// Swap the content with \a other, of same type.
+ ///
/// Both variants must be built beforehand, because swapping the actual
/// data requires reading it (with as()), and this is not possible on
/// unconstructed variants: it would require some dynamic testing, which
/// should not be the variant's responsability.
- /// Swapping between built and ((possibly) non-built is done with
+ /// Swapping between built and (possibly) non-built is done with
/// variant::move ().
template <typename T>
void
std::swap (as<T>(), other.as<T>());
}
- /// Assign the content of \a other to this.
+ /// Move the content of \a other to this.
+ ///
/// Destroys \a other.
template <typename T>
void
}
/// Copy the content of \a other to this.
- /// Destroys \a other.
template <typename T>
void
copy (const variant<S>& other)
tname = YY_NULL;])[
}
+ private:
/// Prohibit blind copies.
- private:
- self_type& operator=(const self_type&)
- {
- abort ();
- }
-
- variant (const self_type&)
- {
- abort ();
- }
+ self_type& operator=(const self_type&);
+ variant (const self_type&);
- private:
/// A buffer large enough to store any of the semantic values.
/// Long double is chosen as it has the strongest alignment
/// constraints.
long double align_me;
char raw[S];
} buffer;]b4_parse_assert_if([
- /// Whether something is contained.
+
+ /// Whether the content is built.
bool built;
/// If defined, the name of the stored type.
const char* tname;])[
b4_parser_class_name::make_[]b4_symbol_([$1], [id]) (dnl
b4_join(b4_symbol_if([$1], [has_type],
[const b4_symbol([$1], [type])& v]),
- b4_locations_if([const location_type& l])))
+ b4_locations_if([const location_type& l])))[
{
- return symbol_type (b4_join([token::b4_symbol([$1], [id])],
- b4_symbol_if([$1], [has_type], [v]),
- b4_locations_if([l])));
+ symbol_type res (token::]b4_symbol([$1], [id])[]b4_locations_if([, l])[);
+ ]b4_symbol_if([$1], [has_type], [res.value.build (v);])[
+ // ]b4_locations_if([res.location = l;])[
+ return res;
}
-])])])
+]])])])
# b4_symbol_constructor_define