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Fixed issue #171 - added extra operator[] template overloads

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This commit is contained in:
Trevor Welsby 2016-01-23 17:03:45 +10:00
parent 9de14a4861
commit 7e3245786c
3 changed files with 218 additions and 42 deletions
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106
src/json.hpp
View file

@ -3062,8 +3062,6 @@ class basic_json
the object and filled with a `null` value to make `key` a valid reference.
In case the value was `null` before, it is converted to an object.
@note This function is required for compatibility reasons with Clang.
@param[in] key key of the element to access
@return reference to the element at key @a key
@ -3083,25 +3081,9 @@ class basic_json
@since version 1.0.0
*/
template<typename T, std::size_t n>
reference operator[](const T (&key)[n])
reference operator[](T* (&key)[n])
{
// implicitly convert null to object
if (is_null())
{
m_type = value_t::object;
m_value = value_t::object;
}
// at only works for objects
if (is_object())
{
assert(m_value.object != nullptr);
return m_value.object->operator[](key);
}
else
{
throw std::domain_error("cannot use operator[] with " + type_name());
}
return operator[](static_cast<const T>(key));
}
/*!
@ -3134,7 +3116,89 @@ class basic_json
@since version 1.0.0
*/
template<typename T, std::size_t n>
const_reference operator[](const T (&key)[n]) const
const_reference operator[](T* (&key)[n]) const
{
return operator[](static_cast<const T>(key));
}
/*!
@brief access specified object element
Returns a reference to the element at with specified key @a key.
@note If @a key is not found in the object, then it is silently added to
the object and filled with a `null` value to make `key` a valid reference.
In case the value was `null` before, it is converted to an object.
@param[in] key key of the element to access
@return reference to the element at key @a key
@throw std::domain_error if JSON is not an object or null; example:
`"cannot use operator[] with null"`
@complexity Logarithmic in the size of the container.
@liveexample{The example below shows how object elements can be read and
written using the [] operator.,operatorarray__key_type}
@sa @ref at(const typename object_t::key_type&) for access by reference
with range checking
@sa @ref value() for access by value with a default value
@since version 1.0.1
*/
template<typename T>
reference operator[](T* key)
{
// implicitly convert null to object
if (is_null())
{
m_type = value_t::object;
m_value = value_t::object;
}
// at only works for objects
if (is_object())
{
assert(m_value.object != nullptr);
return m_value.object->operator[](key);
}
else
{
throw std::domain_error("cannot use operator[] with " + type_name());
}
}
/*!
@brief read-only access specified object element
Returns a const reference to the element at with specified key @a key. No
bounds checking is performed.
@warning If the element with key @a key does not exist, the behavior is
undefined.
@param[in] key key of the element to access
@return const reference to the element at key @a key
@throw std::domain_error if JSON is not an object; example: `"cannot use
operator[] with null"`
@complexity Logarithmic in the size of the container.
@liveexample{The example below shows how object elements can be read using
the [] operator.,operatorarray__key_type_const}
@sa @ref at(const typename object_t::key_type&) for access by reference
with range checking
@sa @ref value() for access by value with a default value
@since version 1.0.1
*/
template<typename T>
const_reference operator[](T* key) const
{
// at only works for objects
if (is_object())

106
src/json.hpp.re2c
View file

@ -3062,8 +3062,6 @@ class basic_json
the object and filled with a `null` value to make `key` a valid reference.
In case the value was `null` before, it is converted to an object.
@note This function is required for compatibility reasons with Clang.
@param[in] key key of the element to access
@return reference to the element at key @a key
@ -3083,25 +3081,9 @@ class basic_json
@since version 1.0.0
*/
template<typename T, std::size_t n>
reference operator[](const T (&key)[n])
reference operator[](T* (&key)[n])
{
// implicitly convert null to object
if (is_null())
{
m_type = value_t::object;
m_value = value_t::object;
}
// at only works for objects
if (is_object())
{
assert(m_value.object != nullptr);
return m_value.object->operator[](key);
}
else
{
throw std::domain_error("cannot use operator[] with " + type_name());
}
return operator[](static_cast<const T>(key));
}
/*!
@ -3134,7 +3116,89 @@ class basic_json
@since version 1.0.0
*/
template<typename T, std::size_t n>
const_reference operator[](const T (&key)[n]) const
const_reference operator[](T* (&key)[n]) const
{
return operator[](static_cast<const T>(key));
}
/*!
@brief access specified object element
Returns a reference to the element at with specified key @a key.
@note If @a key is not found in the object, then it is silently added to
the object and filled with a `null` value to make `key` a valid reference.
In case the value was `null` before, it is converted to an object.
@param[in] key key of the element to access
@return reference to the element at key @a key
@throw std::domain_error if JSON is not an object or null; example:
`"cannot use operator[] with null"`
@complexity Logarithmic in the size of the container.
@liveexample{The example below shows how object elements can be read and
written using the [] operator.,operatorarray__key_type}
@sa @ref at(const typename object_t::key_type&) for access by reference
with range checking
@sa @ref value() for access by value with a default value
@since version 1.0.1
*/
template<typename T>
reference operator[](T* key)
{
// implicitly convert null to object
if (is_null())
{
m_type = value_t::object;
m_value = value_t::object;
}
// at only works for objects
if (is_object())
{
assert(m_value.object != nullptr);
return m_value.object->operator[](key);
}
else
{
throw std::domain_error("cannot use operator[] with " + type_name());
}
}
/*!
@brief read-only access specified object element
Returns a const reference to the element at with specified key @a key. No
bounds checking is performed.
@warning If the element with key @a key does not exist, the behavior is
undefined.
@param[in] key key of the element to access
@return const reference to the element at key @a key
@throw std::domain_error if JSON is not an object; example: `"cannot use
operator[] with null"`
@complexity Logarithmic in the size of the container.
@liveexample{The example below shows how object elements can be read using
the [] operator.,operatorarray__key_type_const}
@sa @ref at(const typename object_t::key_type&) for access by reference
with range checking
@sa @ref value() for access by value with a default value
@since version 1.0.1
*/
template<typename T>
const_reference operator[](T* key) const
{
// at only works for objects
if (is_object())

48
test/unit.cpp
View file

@ -11504,4 +11504,52 @@ TEST_CASE("regression tests")
{
CHECK(json::parse("\"\\ud80c\\udc60abc\"").get<json::string_t>() == u8"\U00013060abc");
}
SECTION("issue #144 - Cannot index by key of type static constexpr const char*")
{
json j;
// Non-const access with key as "char []"
char array_key[] = "Key1";
CHECK_NOTHROW(j[array_key] = 1);
CHECK(j[array_key] == json(1));
// Non-const access with key as "const char[]"
const char const_array_key[] = "Key2";
CHECK_NOTHROW(j[const_array_key] = 2);
CHECK(j[const_array_key] == json(2));
// Non-const access with key as "char *"
char _ptr_key[] = "Key3";
char * ptr_key = &_ptr_key[0];
CHECK_NOTHROW(j[ptr_key] = 3);
CHECK(j[ptr_key] == json(3));
// Non-const access with key as "const char *"
const char * const_ptr_key = "Key4";
CHECK_NOTHROW(j[const_ptr_key] = 4);
CHECK(j[const_ptr_key] == json(4));
// Non-const access with key as "static constexpr const char *"
static constexpr const char* constexpr_ptr_key = "Key5";
CHECK_NOTHROW(j[constexpr_ptr_key] = 5);
CHECK(j[constexpr_ptr_key] == json(5));
const json j_const = j;
// Non-const access with key as "char []"
CHECK(j_const[array_key] == json(1));
// Non-const access with key as "const char[]"
CHECK(j_const[const_array_key] == json(2));
// Non-const access with key as "char *"
CHECK(j_const[ptr_key] == json(3));
// Non-const access with key as "const char *"
CHECK(j_const[const_ptr_key] == json(4));
// Non-const access with key as "static constexpr const char *"
CHECK(j_const[constexpr_ptr_key] == json(5));
}
}