Logical source lines

In pre-ANSI C compilers, backslash/new-line pairs were allowed only as a means to continue a directive, a string literal, or a character constant to the next line. ANSI C extended the notion so that a backslash/new-line pair can continue anything to the next line. (The result is a ``logical source line.'') Therefore, any code that relied on the separate recognition of tokens on either side of a backslash/new-line pair will not behave as expected.