boostorg/optional
1
0
Fork 1
mirror of https://github.com/boostorg/optional.git synced 2025-07-29 12:07:21 +02:00
Code Issues Packages Projects Releases Wiki Activity

Fixed Trac #10839

Browse Source
This commit is contained in:
Andrzej Krzemienski
2015-03-09 11:50:10 +01:00
parent 59266a2630
commit 0a8a798c3a
10 changed files with 107 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
doc/20_reference.qbk
View File

@ -15,11 +15,13 @@
namespace boost {
template<class T>
template <class T>
class optional
{
public :
public :
typedef T value_type;
// (If T is of reference type, the parameters and results by reference are by value)
optional () noexcept ; ``[link reference_optional_constructor __GO_TO__]``
@ -1137,9 +1139,8 @@ __SPACE__
* [*Requires:] `T` shall meet requirements of __SGI_EQUALITY_COMPARABLE__.
* [*Returns:] If both `x` and `y` are initialized, `(*x == *y)`. If only
`x` or `y` is initialized, `false`. If both are uninitialized, `true`.
* [*Notes:] Pointers have shallow relational operators while `optional` has
deep relational operators. Do not use `operator==` directly in generic
code which expect to be given either an `optional<T>` or a pointer; use
* [*Notes:] This definition guarantees that `optional<T>` not containing a value is compared unequal to any `optional<T>` containing any value, and equal to any other `optional<T>` not containing a value.
Pointers have shallow relational operators while `optional` has deep relational operators. Do not use `operator==` directly in generic code which expect to be given either an `optional<T>` or a pointer; use
__FUNCTION_EQUAL_POINTEES__ instead
* [*Example:]
``
@ -1166,8 +1167,8 @@ __SPACE__
* [*Requires:] Expression `*x < *y` shall be well-formed and its result shall be convertible to `bool`.
* [*Returns:] `(!y) ? false : (!x) ? true : *x < *y`.
* [*Notes:] Pointers have shallow relational operators while `optional` has
deep relational operators. Do not use `operator<` directly in generic code
* [*Notes:] This definition guarantees that `optional<T>` not containing a value is ordered as less than any `optional<T>` containing any value, and equivalent to any other `optional<T>` not containing a value.
Pointers have shallow relational operators while `optional` has deep relational operators. Do not use `operator<` directly in generic code
which expect to be given either an `optional<T>` or a pointer; use __FUNCTION_LESS_POINTEES__ instead. `T` need not be __SGI_LESS_THAN_COMPARABLE__. Only single `operator<` is required. Other relational operations are defined in terms of this one. If `T`'s `operator<` satisfies the axioms of __SGI_LESS_THAN_COMPARABLE__ (transitivity, antisymmetry and irreflexivity), `optinal<T>` is __SGI_LESS_THAN_COMPARABLE__.
* [*Example:]
``