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instance method

Set#<

(self) -> bool

<(p1)

static VALUE
set_i_proper_subset(VALUE set, VALUE other)
{
    check_set(other);
    if (RSET_SIZE(set) >= RSET_SIZE(other)) return Qfalse;
    return set_le(set, other);
}

Alias of #proper_subset?

Returns whether self is a proper subset of the given other_set:

Example

set = Set[*'b'..'e']
set.proper_subset?(set)            # => false
set.proper_subset?(Set[*'a'..'f']) # => true

Related: Methods for Querying.

See also #proper_subset? #<= #- #<< also in 4.0 · 3.4 · 3.3 · 3.2 · 3.1 · 3.0

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