Return an optional containing a value constructed from the arguments.
Declared in <bslstl_optional.h>
template<
class t_TYPE,
class t_INIT_LIST_TYPE,
class... t_ARGS>
bsl::optional<t_TYPE>
make_optional(
std::allocator_arg_t allocatorArg,
bsl::optional<t_TYPE>::allocator_type const& alloc,
std::initializer_list<t_INIT_LIST_TYPE> il,
t_ARGS&&... args);Return an optional object containing a t_TYPE object created by invoking a bsl::optional allocator-extended in_place_t constructor with the specified alloc as the allocator argument, and specified il and args as the constructor arguments. Note that this function will fail to compile if t_TYPE doesn't use allocators.
optional containing a t_TYPE constructed from il and args
| Name | Description |
|---|---|
| allocatorArg | tag selecting the allocator-extended constructor |
| alloc | allocator used to supply memory for the optional |
| il | initializer list forwarded to construct the contained value |
| args | arguments forwarded to construct the contained value |