Diff coverage report for

//

//

// Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)

// Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)

// Copyright (c) 2020 Krystian Stasiowski (sdkrystian@gmail.com)

// Copyright (c) 2020 Krystian Stasiowski (sdkrystian@gmail.com)

// Copyright (c) 2022 Dmitry Arkhipov (grisumbras@gmail.com)

// Copyright (c) 2022 Dmitry Arkhipov (grisumbras@gmail.com)

//

//

// Distributed under the Boost Software License, Version 1.0. (See accompanying

// Distributed under the Boost Software License, Version 1.0. (See accompanying

// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

//

//

// Official repository: https://github.com/boostorg/json

// Official repository: https://github.com/boostorg/json

//

//

#ifndef BOOST_JSON_VALUE_FROM_HPP

#ifndef BOOST_JSON_VALUE_FROM_HPP

#define BOOST_JSON_VALUE_FROM_HPP

#define BOOST_JSON_VALUE_FROM_HPP

#include <boost/core/detail/static_assert.hpp>

#include <boost/core/detail/static_assert.hpp>

#include <boost/json/detail/value_from.hpp>

#include <boost/json/detail/value_from.hpp>

namespace boost {

namespace boost {

namespace json {

namespace json {

/** Convert an object of type `T` to @ref value.

/** Convert an object of type `T` to @ref value.

    This function attempts to convert an object

    This function attempts to convert an object

    of type `T` to @ref value using

    of type `T` to @ref value using

    @li one of @ref value's constructors,

    @li one of @ref value's constructors,

    @li a library-provided generic conversion, or

    @li a library-provided generic conversion, or

    @li a user-provided overload of `tag_invoke`.

    @li a user-provided overload of `tag_invoke`.

    Out of the function supports default constructible types satisfying

    Out of the function supports default constructible types satisfying

    {req_SequenceContainer}, arrays, arithmetic types, `bool`, `std::tuple`,

    {req_SequenceContainer}, arrays, arithmetic types, `bool`, `std::tuple`,

    `std::pair`, `std::optional`, `std::variant`, `std::nullptr_t`, and structs

    `std::pair`, `std::optional`, `std::variant`, `std::nullptr_t`, and structs

    and enums described using Boost.Describe.

    and enums described using Boost.Describe.

    Conversion of other types is done by calling an overload of `tag_invoke`

    Conversion of other types is done by calling an overload of `tag_invoke`

    found by argument-dependent lookup. Its signature should be similar to:

    found by argument-dependent lookup. Its signature should be similar to:

    @code

    @code

    template< class FullContext >

    template< class FullContext >

    void tag_invoke( value_from_tag, value&, T, const Context&, const FullContext& );

    void tag_invoke( value_from_tag, value&, T, const Context&, const FullContext& );

    @endcode

    @endcode

    or

    or

    @code

    @code

    void tag_invoke( value_from_tag, value&, T, const Context& );

    void tag_invoke( value_from_tag, value&, T, const Context& );

    @endcode

    @endcode

    or

    or

    @code

    @code

    void tag_invoke( value_from_tag, value&, T );

    void tag_invoke( value_from_tag, value&, T );

    @endcode

    @endcode

    The overloads are checked for existence in that order and the first that

    The overloads are checked for existence in that order and the first that

    matches will be selected. <br>

    matches will be selected. <br>

    The `ctx` argument can be used either as a tag type to provide conversions

    The `ctx` argument can be used either as a tag type to provide conversions

    for third-party types, or to pass extra data to the conversion function.

    for third-party types, or to pass extra data to the conversion function.

    Overloads **(2)** and **(4)** construct their return value using the

    Overloads **(2)** and **(4)** construct their return value using the

    @ref storage_ptr `sp`, which ensures that the memory resource is correctly

    @ref storage_ptr `sp`, which ensures that the memory resource is correctly

    propagated.

    propagated.

    @par Exception Safety

    @par Exception Safety

    Strong guarantee.

    Strong guarantee.

    @tparam T The type of the object to convert.

    @tparam T The type of the object to convert.

    @tparam Context The type of context passed to the conversion function.

    @tparam Context The type of context passed to the conversion function.

    @param t The object to convert.

    @param t The object to convert.

    @param ctx Context passed to the conversion function.

    @param ctx Context passed to the conversion function.

    @param jv @ref value out parameter.

    @param jv @ref value out parameter.

    @see @ref value_from_tag, @ref value_to,

    @see @ref value_from_tag, @ref value_to,

    <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1895r0.pdf">

    <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1895r0.pdf">

        tag_invoke: A general pattern for supporting customisable functions</a>

        tag_invoke: A general pattern for supporting customisable functions</a>

*/

*/

/// @{

/// @{

template< class T, class Context >

template< class T, class Context >

void

void

    T&& t,

    T&& t,

    Context const& ctx,

    Context const& ctx,

    value& jv)

    value& jv)

{

{

    using bare_T = detail::remove_cvref<T>;

    using bare_T = detail::remove_cvref<T>;

    BOOST_CORE_STATIC_ASSERT((

    BOOST_CORE_STATIC_ASSERT((

        detail::conversion_round_trips<

        detail::conversion_round_trips<

            Context, bare_T, detail::value_from_conversion>::value));

            Context, bare_T, detail::value_from_conversion>::value));

    using cat = detail::value_from_category<Context, bare_T>;

    using cat = detail::value_from_category<Context, bare_T>;

/** Overload

/** Overload

   @param t

   @param t

   @param ctx

   @param ctx

   @param sp A storage pointer referring to the memory resource to use for the

   @param sp A storage pointer referring to the memory resource to use for the

   returned @ref value.

   returned @ref value.

   @return Overloads **(2)** and **(4)** return `t` converted to @ref value.

   @return Overloads **(2)** and **(4)** return `t` converted to @ref value.

   Overloads **(1)** and **3** return `void` instead and pass their result via

   Overloads **(1)** and **3** return `void` instead and pass their result via

   the out parameter `jv`.

   the out parameter `jv`.

*/

*/

template< class T, class Context >

template< class T, class Context >

#ifndef BOOST_JSON_DOCS

#ifndef BOOST_JSON_DOCS

typename std::enable_if<

typename std::enable_if<

    !std::is_same< detail::remove_cvref<Context>, storage_ptr >::value &&

    !std::is_same< detail::remove_cvref<Context>, storage_ptr >::value &&

    !std::is_same< detail::remove_cvref<Context>, value >::value,

    !std::is_same< detail::remove_cvref<Context>, value >::value,

    value >::type

    value >::type

#else

#else

value

value

#endif

#endif

    T&& t,

    T&& t,

    Context const& ctx,

    Context const& ctx,

    storage_ptr sp = {})

    storage_ptr sp = {})

{

{

/// Overload

/// Overload

template<class T>

template<class T>

void

void

    T&& t,

    T&& t,

    value& jv)

    value& jv)

{

{

/// Overload

/// Overload

template<class T>

template<class T>

value

value

    T&& t,

    T&& t,

    storage_ptr sp = {})

    storage_ptr sp = {})

{

{

   return value_from(

   return value_from(

}

}

/// @}

/// @}

/** Determine if `T` can be converted to @ref value.

/** Determine if `T` can be converted to @ref value.

    If `T` can be converted to @ref value via a call to @ref value_from, the

    If `T` can be converted to @ref value via a call to @ref value_from, the

    static data member `value` is defined as `true`. Otherwise, `value` is

    static data member `value` is defined as `true`. Otherwise, `value` is

    defined as `false`.

    defined as `false`.

    @see @ref value_from.

    @see @ref value_from.

*/

*/

#ifdef BOOST_JSON_DOCS

#ifdef BOOST_JSON_DOCS

template<class T>

template<class T>

using has_value_from = __see_below__;

using has_value_from = __see_below__;

#else

#else

template<class T>

template<class T>

using has_value_from = detail::can_convert<

using has_value_from = detail::can_convert<

    detail::remove_cvref<T>, detail::value_from_conversion>;

    detail::remove_cvref<T>, detail::value_from_conversion>;

#endif

#endif

} // namespace json

} // namespace json

} // namespace boost

} // namespace boost

#endif

#endif