Updated nlohmann::basicjson::operator[] (markdown)

nlohmann::basicjson::operator[].md

@@ -9,9 +9,9 @@ const_reference operator[](const object_t::key_type& key) const   // 4
 
 ## Description
 
-1. Returns a reference to the element at specified index `idx`. No bounds checking is performed. In case `idx > size()`, null values are inserted between `size()` and `idx - 1` (only works for arrays).
+1. Returns a reference to the element at specified index `idx`. In case `idx > size()`, null values are inserted between `size()` and `idx` before (only works for arrays).
 2. Returns a reference to the element at specified index `idx`. No bounds checking is performed and no values will be inserted (only works for arrays).
-3. Returns a reference to the value that is mapped to a key equivalent to `key`, performing an insertion if such key does not already exist. If an insertion is performed, the mapped value is value-initialized (default-constructed for class types, zero-initialized otherwise) and a reference to it is returned. No bounds checking is performed (only works for objects).
+3. Returns a reference to the value that is mapped to a key equivalent to `key`, performing an insertion of a null value if such key does not already exist and returns a reference to this value (only works for objects).
 4. Returns a reference to the mapped value of the element with key equivalent to `key`. No bounds checking is performed and no values will be inserted (only works for objects).
 
 ## Parameters
@@ -21,14 +21,16 @@ const_reference operator[](const object_t::key_type& key) const   // 4
 
 ## Return value
 
-Reference to the specified value.
+Reference to the specified value. In case of 1 and 3, the reference may be to a newly inserted null value.
 
 ## Complexity
 
-1. Constant.
-2. Logarithmic in the size of the container.
+1. Linear in the distance between `size()` and `idx` if `idx > size()`, constant otherwise.
+2. Constant.
+3. Logarithmic in the size of the container.
+4. Logarithmic in the size of the container.
 
 ## Exceptions
 
 1. `std::runtime_error` when called on a JSON container with other type than `array`.
-2. `std::runtime_error` when called on a JSON container with other type than `object`.
+2. `std::runtime_error` when called on a JSON container with other type than `object`.