<divclass="example-wrap"><preclass="rust rust-example-rendered"><code><spanclass="comment">// In this example validator returns immediately, but since it is required to return
// anything that implements `IntoFuture` trait, it can be extended to query database or to
</div></details><detailsclass="rustdoc-toggle"open><summary><sectionid="associatedtype.Error"class="associatedtype trait-impl has-srclink"><ahref="#associatedtype.Error"class="anchor"></a><h4class="code-header">type <aclass="associatedtype">Error</a> = Error</h4></section></summary><divclass='docblock'><p>Errors produced by the service.</p>
</div></details><detailsclass="rustdoc-toggle"open><summary><sectionid="associatedtype.Transform"class="associatedtype trait-impl has-srclink"><ahref="#associatedtype.Transform"class="anchor"></a><h4class="code-header">type <aclass="associatedtype">Transform</a> = AuthenticationMiddleware<S, F, T></h4></section></summary><divclass='docblock'><p>The <code>TransformService</code> value created by this factory</p>
</div></details><detailsclass="rustdoc-toggle"open><summary><sectionid="associatedtype.InitError"class="associatedtype trait-impl has-srclink"><ahref="#associatedtype.InitError"class="anchor"></a><h4class="code-header">type <aclass="associatedtype">InitError</a> = <aclass="primitive"href="https://doc.rust-lang.org/nightly/std/primitive.unit.html">()</a></h4></section></summary><divclass='docblock'><p>Errors produced while building a transform service.</p>
</div></details></div></details><detailsclass="rustdoc-toggle implementors-toggle"><summary><sectionid="impl-Borrow%3CT%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="impl has-srclink"><aclass="srclink rightside"href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#209">source</a><ahref="#impl-Borrow%3CT%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="anchor"></a><h3class="code-header in-band">impl<T><aclass="trait"href="https://doc.rust-lang.org/nightly/core/borrow/trait.Borrow.html"title="trait core::borrow::Borrow">Borrow</a><T> for T <spanclass="where fmt-newline">where<br> T: ?<aclass="trait"href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>, </span></h3></section></summary><divclass="impl-items"><detailsclass="rustdoc-toggle method-toggle"open><summary><sectionid="method.borrow"class="method trait-impl has-srclink"><spanclass="rightside"><spanclass="since"title="const unstable">const: <ahref="https://github.com/rust-lang/rust/issues/91522"title="Tracking issue for const_borrow">unstable</a></span> · <aclass="srclink"href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#211">source</a></span><ahref="#method.borrow"class="anchor"></a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/nightly/core/borrow/trait.Borrow.html#tymethod.borrow"class="fnname">borrow</a>(&self) -><aclass="primitive"href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&</a>T</h4></section></summary><divclass='docblock'><p>Immutably borrows from an owned value. <ahref="https://doc.rust-lang.org/nightly/core/borrow/trait.Borrow.html#tymethod.borrow">Read more</a></p>
</div></details></div></details><detailsclass="rustdoc-toggle implementors-toggle"><summary><sectionid="impl-BorrowMut%3CT%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="impl has-srclink"><aclass="srclink rightside"href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#218">source</a><ahref="#impl-BorrowMut%3CT%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="anchor"></a><h3class="code-header in-band">impl<T><aclass="trait"href="https://doc.rust-lang.org/nightly/core/borrow/trait.BorrowMut.html"title="trait core::borrow::BorrowMut">BorrowMut</a><T> for T <spanclass="where fmt-newline">where<br> T: ?<aclass="trait"href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>, </span></h3></section></summary><divclass="impl-items"><detailsclass="rustdoc-toggle method-toggle"open><summary><sectionid="method.borrow_mut"class="method trait-impl has-srclink"><spanclass="rightside"><spanclass="since"title="const unstable">const: <ahref="https://github.com/rust-lang/rust/issues/91522"title="Tracking issue for const_borrow">unstable</a></span> · <aclass="srclink"href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#219">source</a></span><ahref="#method.borrow_mut"class="anchor"></a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/nightly/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut"class="fnname">borrow_mut</a>(&mut self) -><aclass="primitive"href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&mut </a>T</h4></section></summary><divclass='docblock'><p>Mutably borrows from an owned value. <ahref="https://doc.rust-lang.org/nightly/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut">Read more</a></p>
</div></details></div></details><detailsclass="rustdoc-toggle implementors-toggle"><summary><sectionid="impl-From%3CT%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="impl has-srclink"><aclass="srclink rightside"href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#559">source</a><ahref="#impl-From%3CT%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="anchor"></a><h3class="code-header in-band">impl<T><aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html"title="trait core::convert::From">From</a><T> for T</h3></section></summary><divclass="impl-items"><detailsclass="rustdoc-toggle method-toggle"open><summary><sectionid="method.from"class="method trait-impl has-srclink"><spanclass="rightside"><spanclass="since"title="const unstable">const: <ahref="https://github.com/rust-lang/rust/issues/88674"title="Tracking issue for const_convert">unstable</a></span> · <aclass="srclink"href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#561">source</a></span><ahref="#method.from"class="anchor"></a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/nightly/core/convert/trait.From.html#tymethod.from"class="fnname">from</a>(t: T) -> T</h4></section></summary><divclass="docblock"><p>Returns the argument unchanged.</p>
</div></details></div></details><detailsclass="rustdoc-toggle implementors-toggle"><summary><sectionid="impl-Instrument-for-HttpAuthentication%3CT%2C%20F%3E"class="impl has-srclink"><aclass="srclink rightside"href="https://docs.rs/tracing/0.1.36/src/tracing/instrument.rs.html#276">source</a><ahref="#impl-Instrument-for-HttpAuthentication%3CT%2C%20F%3E"class="anchor"></a><h3class="code-header in-band">impl<T><aclass="trait"href="https://docs.rs/tracing/0.1.36/tracing/instrument/trait.Instrument.html"title="trait tracing::instrument::Instrument">Instrument</a> for T</h3></section></summary><divclass="impl-items"><detailsclass="rustdoc-toggle method-toggle"open><summary><sectionid="method.instrument"class="method trait-impl has-srclink"><aclass="srclink rightside"href="https://docs.rs/tracing/0.1.36/src/tracing/instrument.rs.html#82">source</a><ahref="#method.instrument"class="anchor"></a><h4class="code-header">fn <ahref="https://docs.rs/tracing/0.1.36/tracing/instrument/trait.Instrument.html#method.instrument"class="fnname">instrument</a>(self, span: <aclass="struct"href="https://docs.rs/tracing/0.1.36/tracing/span/struct.Span.html"title="struct tracing::span::Span">Span</a>) -><aclass="struct"href="https://docs.rs/tracing/0.1.36/tracing/instrument/struct.Instrumented.html"title="struct tracing::instrument::Instrumented">Instrumented</a><Self></h4></section></summary><divclass='docblock'><p>Instruments this type with the provided <ahref="https://docs.rs/tracing/0.1.36/tracing/span/struct.Span.html"title="Span"><code>Span</code></a>, returning an
</div></details><detailsclass="rustdoc-toggle method-toggle"open><summary><sectionid="method.in_current_span"class="method trait-impl has-srclink"><aclass="srclink rightside"href="https://docs.rs/tracing/0.1.36/src/tracing/instrument.rs.html#121">source</a><ahref="#method.in_current_span"class="anchor"></a><h4class="code-header">fn <ahref="https://docs.rs/tracing/0.1.36/tracing/instrument/trait.Instrument.html#method.in_current_span"class="fnname">in_current_span</a>(self) -><aclass="struct"href="https://docs.rs/tracing/0.1.36/tracing/instrument/struct.Instrumented.html"title="struct tracing::instrument::Instrumented">Instrumented</a><Self></h4></section></summary><divclass='docblock'><p>Instruments this type with the <ahref="https://docs.rs/tracing/0.1.36/tracing/span/struct.Span.html#method.current">current</a><ahref="https://docs.rs/tracing/0.1.36/tracing/span/struct.Span.html"><code>Span</code></a>, returning an
</div></details></div></details><detailsclass="rustdoc-toggle implementors-toggle"><summary><sectionid="impl-Same%3CT%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="impl has-srclink"><aclass="srclink rightside"href="https://docs.rs/typenum/1.15.0/src/typenum/type_operators.rs.html#34">source</a><ahref="#impl-Same%3CT%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="anchor"></a><h3class="code-header in-band">impl<T><aclass="trait"href="https://docs.rs/typenum/1.15.0/typenum/type_operators/trait.Same.html"title="trait typenum::type_operators::Same">Same</a><T> for T</h3></section></summary><divclass="impl-items"><detailsclass="rustdoc-toggle"open><summary><sectionid="associatedtype.Output"class="associatedtype trait-impl has-srclink"><ahref="#associatedtype.Output"class="anchor"></a><h4class="code-header">type <ahref="https://docs.rs/typenum/1.15.0/typenum/type_operators/trait.Same.html#associatedtype.Output"class="associatedtype">Output</a> = T</h4></section></summary><divclass='docblock'><p>Should always be <code>Self</code></p>
</div></details></div></details><detailsclass="rustdoc-toggle implementors-toggle"><summary><sectionid="impl-ToOwned-for-HttpAuthentication%3CT%2C%20F%3E"class="impl has-srclink"><aclass="srclink rightside"href="https://doc.rust-lang.org/nightly/src/alloc/borrow.rs.html#83">source</a><ahref="#impl-ToOwned-for-HttpAuthentication%3CT%2C%20F%3E"class="anchor"></a><h3class="code-header in-band">impl<T><aclass="trait"href="https://doc.rust-lang.org/nightly/alloc/borrow/trait.ToOwned.html"title="trait alloc::borrow::ToOwned">ToOwned</a> for T <spanclass="where fmt-newline">where<br> T: <aclass="trait"href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html"title="trait core::clone::Clone">Clone</a>, </span></h3></section></summary><divclass="impl-items"><detailsclass="rustdoc-toggle"open><summary><sectionid="associatedtype.Owned"class="associatedtype trait-impl has-srclink"><ahref="#associatedtype.Owned"class="anchor"></a><h4class="code-header">type <ahref="https://doc.rust-lang.org/nightly/alloc/borrow/trait.ToOwned.html#associatedtype.Owned"class="associatedtype">Owned</a> = T</h4></section></summary><divclass='docblock'><p>The resulting type after obtaining ownership.</p>
</div></details><detailsclass="rustdoc-toggle method-toggle"open><summary><sectionid="method.to_owned"class="method trait-impl has-srclink"><aclass="srclink rightside"href="https://doc.rust-lang.org/nightly/src/alloc/borrow.rs.html#88">source</a><ahref="#method.to_owned"class="anchor"></a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/nightly/alloc/borrow/trait.ToOwned.html#tymethod.to_owned"class="fnname">to_owned</a>(&self) -> T</h4></section></summary><divclass='docblock'><p>Creates owned data from borrowed data, usually by cloning. <ahref="https://doc.rust-lang.org/nightly/alloc/borrow/trait.ToOwned.html#tymethod.to_owned">Read more</a></p>
</div></details><detailsclass="rustdoc-toggle method-toggle"open><summary><sectionid="method.clone_into"class="method trait-impl has-srclink"><aclass="srclink rightside"href="https://doc.rust-lang.org/nightly/src/alloc/borrow.rs.html#92">source</a><ahref="#method.clone_into"class="anchor"></a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/nightly/alloc/borrow/trait.ToOwned.html#method.clone_into"class="fnname">clone_into</a>(&self, target: <aclass="primitive"href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&mut </a>T)</h4></section></summary><divclass='docblock'><p>Uses borrowed data to replace owned data, usually by cloning. <ahref="https://doc.rust-lang.org/nightly/alloc/borrow/trait.ToOwned.html#method.clone_into">Read more</a></p>
</div></details></div></details><detailsclass="rustdoc-toggle implementors-toggle"><summary><sectionid="impl-TryFrom%3CU%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="impl has-srclink"><aclass="srclink rightside"href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#600">source</a><ahref="#impl-TryFrom%3CU%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="anchor"></a><h3class="code-header in-band">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U> for T <spanclass="where fmt-newline">where<br> U: <aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.Into.html"title="trait core::convert::Into">Into</a><T>, </span></h3></section></summary><divclass="impl-items"><detailsclass="rustdoc-toggle"open><summary><sectionid="associatedtype.Error-1"class="associatedtype trait-impl has-srclink"><ahref="#associatedtype.Error-1"class="anchor"></a><h4class="code-header">type <ahref="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error"class="associatedtype">Error</a> = <aclass="enum"href="https://doc.rust-lang.org/nightly/core/convert/enum.Infallible.html"title="enum core::convert::Infallible">Infallible</a></h4></section></summary><divclass='docblock'><p>The type returned in the event of a conversion error.</p>
</div></details></div></details><detailsclass="rustdoc-toggle implementors-toggle"><summary><sectionid="impl-TryInto%3CU%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="impl has-srclink"><aclass="srclink rightside"href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#585">source</a><ahref="#impl-TryInto%3CU%3E-for-HttpAuthentication%3CT%2C%20F%3E"class="anchor"></a><h3class="code-header in-band">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryInto.html"title="trait core::convert::TryInto">TryInto</a><U> for T <spanclass="where fmt-newline">where<br> U: <aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>, </span></h3></section></summary><divclass="impl-items"><detailsclass="rustdoc-toggle"open><summary><sectionid="associatedtype.Error-2"class="associatedtype trait-impl has-srclink"><ahref="#associatedtype.Error-2"class="anchor"></a><h4class="code-header">type <ahref="https://doc.rust-lang.org/nightly/core/convert/trait.TryInto.html#associatedtype.Error"class="associatedtype">Error</a> = <U as <aclass="trait"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="associatedtype"href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a></h4></section></summary><divclass='docblock'><p>The type returned in the event of a conversion error.</p>
</div></details><detailsclass="rustdoc-toggle method-toggle"open><summary><sectionid="method.with_current_subscriber"class="method trait-impl has-srclink"><aclass="srclink rightside"href="https://docs.rs/tracing/0.1.36/src/tracing/instrument.rs.html#221">source</a><ahref="#method.with_current_subscriber"class="anchor"></a><h4class="code-header">fn <ahref="https://docs.rs/tracing/0.1.36/tracing/instrument/trait.WithSubscriber.html#method.with_current_subscriber"class="fnname">with_current_subscriber</a>(self) -><aclass="struct"href="https://docs.rs/tracing/0.1.36/tracing/instrument/struct.WithDispatch.html"title="struct tracing::instrument::WithDispatch">WithDispatch</a><Self></h4></section></summary><divclass='docblock'><p>Attaches the current <ahref="https://docs.rs/tracing/0.1.36/tracing/dispatcher/index.html#setting-the-default-subscriber">default</a><ahref="https://docs.rs/tracing-core/0.1.22/tracing_core/subscriber/trait.Subscriber.html"><code>Subscriber</code></a> to this type, returning a