gdb: Fortran Operators
15.4.6.1 Fortran Operators and Expressions
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Operators must be defined on values of specific types. For instance,
'+' is defined on numbers, but not on characters or other non-
arithmetic types. Operators are often defined on groups of types.
'**'
The exponentiation operator. It raises the first operand to the
power of the second one.
':'
The range operator. Normally used in the form of array(low:high)
to represent a section of array.
'%'
The access component operator. Normally used to access elements in
derived types. Also suitable for unions. As unions aren't part of
regular Fortran, this can only happen when accessing a register
that uses a gdbarch-defined union type.