[#bsl-operator_lt-016]
= xref:bsl.adoc[bsl]::operator<
:relfileprefix: ../
:mrdocs:

Less‐than operators

== Synopses

Declared in `<bslstl_optional.h>`

Return `true` if the specified `lhs` iterator is earlier in the underlying sequence than the specified `rhs` iterator, and `false` otherwise.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
bool
xref:bsl/operator_lt-03.adoc[operator<](
    xref:bsl/vector_UintPtrConversionIterator.adoc[vector_UintPtrConversionIterator] const& lhs,
    xref:bsl/vector_UintPtrConversionIterator.adoc[vector_UintPtrConversionIterator] const& rhs);
----

[.small]#xref:bsl/operator_lt-03.adoc[_» more..._]#

Return whether the left‐hand operand is ordered before the right.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    class t_LHS_TYPE,
    class t_RHS_TYPE>
constexpr
bool
xref:bsl/operator_lt-0b.adoc[operator<](
    xref:bsl/optional-072.adoc[bsl::optional<t_LHS_TYPE>] const& lhs,
    xref:bsl/optional-072.adoc[bsl::optional<t_RHS_TYPE>] const& rhs);
----

[.small]#xref:bsl/operator_lt-0b.adoc[_» more..._]#

Return whether the left‐hand operand is ordered before the right.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    class t_LHS_TYPE,
    class t_RHS_TYPE>
constexpr
bool
xref:bsl/operator_lt-00.adoc[operator<](
    xref:bsl/optional-072.adoc[bsl::optional<t_LHS_TYPE>] const& lhs,
    t_RHS_TYPE const& rhs);
----

[.small]#xref:bsl/operator_lt-00.adoc[_» more..._]#

Return whether the left‐hand operand is ordered before the right.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    class t_LHS_TYPE,
    class t_RHS_TYPE>
constexpr
bool
xref:bsl/operator_lt-06.adoc[operator<](
    t_LHS_TYPE const& lhs,
    xref:bsl/optional-072.adoc[bsl::optional<t_RHS_TYPE>] const& rhs);
----

[.small]#xref:bsl/operator_lt-06.adoc[_» more..._]#

Return whether the left‐hand operand is ordered before the right.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    class t_LHS_TYPE,
    class t_RHS_TYPE>
constexpr
bool
xref:bsl/operator_lt-010.adoc[operator<](
    xref:bsl/optional-072.adoc[bsl::optional<t_LHS_TYPE>] const& lhs,
    std::optional<t_RHS_TYPE> const& rhs);
----

[.small]#xref:bsl/operator_lt-010.adoc[_» more..._]#

Compare a `std::optional` with a `bsl::optional` using less‐than.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    class t_LHS_TYPE,
    class t_RHS_TYPE>
constexpr
bool
xref:bsl/operator_lt-01f.adoc[operator<](
    std::optional<t_LHS_TYPE> const& lhs,
    xref:bsl/optional-072.adoc[bsl::optional<t_RHS_TYPE>] const& rhs);
----

[.small]#xref:bsl/operator_lt-01f.adoc[_» more..._]#

Return whether the specified stacks compare lexicographically; see the non‐member `operator<` in the `bsl` namespace.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
bool
xref:bsl/operator_lt-08.adoc[operator<](
    xref:bsl/stack-05.adoc[stack<VAL, CONT>] const& lhs,
    xref:bsl/stack-05.adoc[stack<VAL, CONT>] const& rhs);
----

[.small]#xref:bsl/operator_lt-08.adoc[_» more..._]#

Return whether `lhs` is lexicographically less than `rhs`.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    class VALUE,
    class CONTAINER>
bool
xref:bsl/operator_lt-0c.adoc[operator<](
    xref:bsl/stack-05.adoc[stack<VALUE, CONTAINER>] const& lhs,
    xref:bsl/stack-05.adoc[stack<VALUE, CONTAINER>] const& rhs);
----

[.small]#xref:bsl/operator_lt-0c.adoc[_» more..._]#

Return `true` if `lhs` is less than `rhs`.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    class t_HEAD,
    class... t_TAIL>
bool
xref:bsl/operator_lt-01d.adoc[operator<](
    xref:bsl/variant.adoc[variant<t_HEAD, t_TAIL...>] const& lhs,
    xref:bsl/variant.adoc[variant<t_HEAD, t_TAIL...>] const& rhs);
----

[.small]#xref:bsl/operator_lt-01d.adoc[_» more..._]#

Return whether the specified queues compare lexicographically; see the non‐member `operator<` in the `bsl` namespace.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
bool
xref:bsl/operator_lt-0e1.adoc[operator<](
    xref:bsl/queue-0a5.adoc[queue<VALUE2, CONTAINER2>] const& lhs,
    xref:bsl/queue-0a5.adoc[queue<VALUE2, CONTAINER2>] const& rhs);
----

[.small]#xref:bsl/operator_lt-0e1.adoc[_» more..._]#

Return `true` if `lhs` is lexicographically less than `rhs`.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    class VALUE,
    class CONTAINER>
bool
xref:bsl/operator_lt-0ef.adoc[operator<](
    xref:bsl/queue-0a5.adoc[queue<VALUE, CONTAINER>] const& lhs,
    xref:bsl/queue-0a5.adoc[queue<VALUE, CONTAINER>] const& rhs);
----

[.small]#xref:bsl/operator_lt-0ef.adoc[_» more..._]#

Return `true` if `__x` is lexicographically less than `__y`.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    class _Tp,
    class _Alloc>
bool
xref:bsl/operator_lt-05.adoc[operator<](
    xref:bsl/slist.adoc[slist<_Tp, _Alloc>] const& __x,
    xref:bsl/slist.adoc[slist<_Tp, _Alloc>] const& __y);
----

[.small]#xref:bsl/operator_lt-05.adoc[_» more..._]#

== Return Value

* `true` if `lhs` precedes `rhs` in the underlying sequence
* `true` if `lhs` is ordered before `rhs`, and `false` otherwise
* `true` if `lhs` is lexicographically less than `rhs`
* `true` if `lhs` is less than `rhs`
* `true` if `lhs` is lexicographically less than `rhs`, otherwise `false`
* `true` if `lhs` is lexicographically less than `rhs`, otherwise `false`
* `true` if `__x < __y`, and `false` otherwise

== Parameters

[cols="1,4"]
|===
| Name| Description
| *lhs*
| left‐hand operand
| *rhs*
| right‐hand operand
| *__x*
| left‐hand list
| *__y*
| right‐hand list
|===


[.small]#Created with https://www.mrdocs.com[MrDocs]#