BloombergLP::bdlb::NullableValueRef

Name

Description

value_type

value_type is an alias for the template parameter TYPE, and represents the type of the object managed by the wrapped nullable object.

Name

Description

NullableValueRef [constructor]

Constructors

operator=

Assignment operators

addressOr

Return an address providing non‐modifiable access to the underlying object of a (template parameter) TYPE if this object is non‐null, and the specified address otherwise.

emplace

Assign to the target the value of the (template parameter) TYPE created in place using the specified args and return a reference providing modifiable access to the underlying TYPE object. If this optional object already contains an object (`true == hasValue()`), that object is destroyed before the new object is created. Note that if the constructor of TYPE throws an exception this object is left in a disengaged state.

has_value

Return true if the target contains a value, and false otherwise.

isNull

Return false if the target contains a value, and true otherwise. Note that this accessor is provided purely for compatibility with NullableValue and NullableAllocatedValue, and its use is discouraged in favor of has_value.

makeValueInplace

Assign to this nullable object the value of the (template parameter) TYPE created in place using the specified args. Return a reference providing modifiable access to the created (value) object. The object is also accessible via the value method. If this nullable object already contains an object (false == isNull()), that object is destroyed before the new object is created. If TYPE has the trait bslma::UsesBslmaAllocator (TYPE is allocator‐enabled) the allocator specified at the construction of this nullable object is used to supply memory to the value object. Attempts to explicitly specify via args another allocator to supply memory to the created (value) object are disallowed by the compiler. Note that if the constructor of TYPE throws an exception this object is left in the null state.

operator*

Dereference operators

operator‐>

Member access operators

reset

Reset the target to the default constructed state (i.e., to have the null value).

value

value overloads

valueOr

Return the value of the underlying object of a (template parameter) TYPE if this object is non‐null, and the specified otherValue otherwise. Note that this method returns by value, so may be inefficient in some contexts.

valueOrNull

Return an address providing non‐modifiable access to the underlying object of a (template parameter) TYPE if this object is non‐null, and 0 otherwise.

value_or

Return the value of the underlying object of a (template parameter) TYPE if the target is non‐null, and the specified default_value otherwise. Note that this method returns by value, so may be inefficient in some contexts.

operator bool

Return true if the target holds a value, and false otherwise.

Name

Description

BloombergLP::bdlb::ConstNullableValueRef

This class is a wrapper for either a bsl::optional or NullableAllocatedValue, and provides non‐modifiable access to the wrapped object.

Name

Description

operator!=

See the overload above for contract.

operator!=

Return true if the specified lhs and rhs objects do not have the same value, and false otherwise. A nullable wrappers and a value of some type do not have the same value if either the nullable wrappers is null, or its underlying value does not compare equal to the other value. Note that this function will fail to compile if LHS_TYPE and RHS_TYPE are not compatible.

operator!=

Return true if the specified lhs is not null, and false otherwise.

operator!=

Return true if the specified lhs and rhs nullable objects do not have the same value, and false otherwise. Two nullable wrappers do not have the same value if one is null and the other is non‐null, or if both are non‐null and the values of their underlying objects do not compare equal. Note that this function will fail to compile if LHS_TYPE and RHS_TYPE are not compatible.

operator<

Return false. bsl::nullopt never orders after a NullableValueRef.

operator<

Return true if the specified lhs nullable wrapper is ordered before the specified rhs, and false otherwise. lhs is ordered before rhs if lhs is null or lhs.value() is ordered before rhs.

operator<

Return true if the specified lhs nullable wrapper is ordered before the specified rhs nullable object, and false otherwise. lhs is ordered before rhs if lhs is null and rhs is non‐null or if both are non‐null and lhs.value() is ordered before rhs.value(). Note that this function will fail to compile if LHS_TYPE and RHS_TYPE are not compatible.

operator<

See the overload above for contract.

operator<=

Return true if the specified lhs nullable wrapper is ordered before the specified rhs or lhs and rhs have the same value, and false otherwise. (See operator< and operator==.) Note that this operator returns !(rhs < lhs).

operator<=

See the overload above for contract.

operator<=

Return true if the specified lhs nullable wrapper is ordered before the specified rhs nullable object or lhs and rhs have the same value, and false otherwise. (See operator< and operator==.) Note that this function will fail to compile if LHS_TYPE and RHS_TYPE are not compatible.

operator<=

Return true if the specified lhs is null, and false otherwise.

operator==

Return true if the specified lhs is null, and false otherwise.

operator==

See the overload above for contract.

operator==

Return true if the specified lhs and rhs nullable wrappers have the same value, and false otherwise. Two nullable wrappers have the same value if both targets are null, or if both are non‐null and the values of their underlying objects compare equal. Note that this function will fail to compile if LHS_TYPE and RHS_TYPE are not compatible.

operator==

Return true if the specified lhs and rhs objects have the same value, and false otherwise. A nullable wrapper and a value of some type have the same value if the nullable wrapper is non‐null and the underlying value of it's target compares equal to the other value. Note that this function will fail to compile if LHS_TYPE and RHS_TYPE are not compatible.

operator>

See the overload above for contract.

operator>

Return true if the specified lhs nullable wrapper is ordered after the specified rhs nullable object, and false otherwise. lhs is ordered after rhs if lhs is non‐null and rhs is null or if both are non‐null and lhs.value() is ordered after rhs.value(). Note that this operator returns rhs < lhs when both operands are of bsl::optional type. Also note that this function will fail to compile if LHS_TYPE and RHS_TYPE are not compatible.

operator>

Return true if the specified lhs nullable wrapper is ordered after the specified rhs, and false otherwise. lhs is ordered after rhs if lhs is not null and lhs.value() is ordered after rhs. Note that this operator returns rhs < lhs.

operator>

Return true if the specified lhs is not null, and false otherwise.

operator>=

Return true if the specified lhs nullable wrapper is ordered after the specified rhs or lhs and rhs have the same value, and false otherwise. (See operator> and operator==.) Note that this operator returns !(lhs < rhs).

operator>=

See the overload above for contract.

operator>=

Return true if the specified lhs nullable object is ordered after the specified rhs nullable wrapper or lhs and rhs have the same value, and false otherwise. (See operator> and operator==.) Note that this operator returns !(lhs < rhs) when both operands are of bsl::optional type. Also note that this function will fail to compile if LHS_TYPE and RHS_TYPE are not compatible.

operator>=

Return true.