Converts a value type to an object reference (type O).
Assembly: mscorlib (in mscorlib.dll)
The following table lists the instruction's hexadecimal and Microsoft Intermediate Language (MSIL) assembly format, along with a brief reference summary:
8C < T >
Convert a value type (of the type specified in valTypeToken) to a true object reference.
The stack transitional behavior, in sequential order, is:
A value type is pushed onto the stack.
The value type is popped from the stack; the box operation is performed.
An object reference to the resulting "boxed" value type is pushed onto the stack.
A value type has two separate representations within the Common Language Infrastructure (CLI):
A 'raw' form used when a value type is embedded within another object or on the stack.
A 'boxed' form, where the data in the value type is wrapped (boxed) into an object so it can exist as an independent entity.
The box instruction converts the 'raw' (unboxed) value type into an object reference (type O). This is accomplished by creating a new object and copying the data from the value type into the newly allocated object. valTypeToken is a metadata token indicating the type of the value type on the stack.
OutOfMemoryException is thrown if there is insufficient memory to satisfy the request.
TypeLoadException is thrown if the class cannot be found. This is typically detected when Microsoft Intermediate Language (MSIL) is converted to native code, rather than at runtime.
The following Emit method overload can use the box opcode:
Available since 4.5
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.1
Available since 8.1