1.4.2 Casting PlTerm to native C-types

PlTerm can be cast to the following types:

PlTerm ::operator term_t(void)

This cast is used for integration with the C-interface primitives.

PlTerm ::operator long(void)

Yields a long if the PlTerm is a Prolog integer or float that can be converted without loss to a long. throws a type_error exception otherwise.

PlTerm ::operator int(void)

Same as for long, but might represent fewer bits.

PlTerm ::operator double(void)

Yields the value as a C double if PlTerm represents a Prolog integer or float.

PlTerm ::operator wchar_t *(void)

PlTerm ::operator char *(void)

Converts the Prolog argument using PL_get_chars() using the flags CVT_ALL|CVT_WRITE|BUF_RING, which implies Prolog atoms and strings are converted to the represented text. All other data is handed to write/1. If the text is static in Prolog, a direct pointer to the string is returned. Otherwise the text is saved in a ring of 16 buffers and must be copied to avoid overwriting.

PlTerm ::operator void *(void)

Extracts pointer value from a term. The term should have been created by PlTerm::PlTerm(void*).