== `sqlite/value.hpp`

=== `value_type`

The https://www.sqlite.org/datatype3.html)[type of a value].

[source,cpp]
----
enum class value_type
{
    // An integral value
    integer = SQLITE_INTEGER,
    // A floating piont value
    floating = SQLITE_FLOAT,
    // A textual value
    text = SQLITE_TEXT,
    // A binary value
    blob = SQLITE_BLOB,
    // No value
    null = SQLITE_NULL,
};

// Get the name as a string
const char * value_type_name(value_type vt);
----

=== `value`

A holder for a sqlite values used for internal APIs.

[source,cpp]
----

struct value
{
    // The value for integers in the database
    typedef sqlite3_int64 int64 ;

    // The type of the value
    value_type type() const;
    // The subtype of the value.
    int subtype() const;

    // Is the held value null
    bool is_null() const;
    // Is the held value is not null
    explicit operator bool () const;
    // Returns the value as an `integer`.
    int64 get_int() const;
    // Returns the value as an `double`.
    double get_double() const;
    // Returns the value as text, i.e. a string_view. Note that this value may be invalidated`.
    cstring_ref get_text() const;
    // Returns the value as blob, i.e. raw memory. Note that this value may be invalidated`.
    blob_view get_blob() const;

    // Best numeric datatype of the value
    value_type numeric_type() const;

    // True if the column is unchanged in an UPDATE against a virtual table.
    // requires sqlite 3.32
    bool nochange() const;
    // True if value originated from a bound parameter
    // requires sqlite 3.31
    bool from_bind() const;


    // Construct value from a handle.
    explicit value(sqlite3_value * value_) noexcept : value_(value_) {}

    // The handle of the value.
    using handle_type = sqlite3_value *;
    // Returns the handle.
    handle_type handle() const;
    handle_type & handle();

    // Get a value that was passed through the pointer interface.
    // A value can be set as a pointer by binding/returning a unique_ptr.
    // Rquires sqlite 3.20
    template<typename T>
    T * get_pointer();

};
----