The ASN1 specification has many primitive data types defined as well as containers for data. The ASN1 data types are generalized to be platform and language independent. Many of the modern scripting languages do not distinguish between an integer and a float, for example, Perl. An integer or a float is just a number in Perl, where as in C++, there are distinct integral types. It is left up to the implementor to map the ASN1 data types to the language's native data types.

The Boost.ASN1 library is one method to bridge the ASN1 specification with the C++ language. This library delivers a number of classes and templates for the various ASN1 data types, allowing for near replacement of a ASN1 specification file.

The classes and templates of the Boost.ASN1 library are designed to be used as actual data types for integrals, strings and containers.

These data types allow for assignment to each other without casting operators when they are in the same type classification, for example, a REAL can cast to a INTEGER without the compiler complaining.