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 <h4 class="subsection">6.1.9 BOZ literal constants</h4>

 <p><a name="index-BOZ-literal-constants-335"></a>
 Besides decimal constants, Fortran also supports binary (<code>b</code>),
 octal (<code>o</code>) and hexadecimal (<code>z</code>) integer constants.  The
 syntax is: &lsquo;<samp><span class="samp">prefix quote digits quote</span></samp>&rsquo;, were the prefix is
 either <code>b</code>, <code>o</code> or <code>z</code>, quote is either <code>'</code> or
 <code>"</code> and the digits are for binary <code>0</code> or <code>1</code>, for
 octal between <code>0</code> and <code>7</code>, and for hexadecimal between
 <code>0</code> and <code>F</code>.  (Example: <code>b'01011101'</code>.)

    <p>Up to Fortran 95, BOZ literals were only allowed to initialize
 integer variables in DATA statements.  Since Fortran 2003 BOZ literals
 are also allowed as argument of <code>REAL</code>, <code>DBLE</code>, <code>INT</code>
 and <code>CMPLX</code>; the result is the same as if the integer BOZ
 literal had been converted by <code>TRANSFER</code> to, respectively,
 <code>real</code>, <code>double precision</code>, <code>integer</code> or <code>complex</code>.
 As GNU Fortran extension the intrinsic procedures <code>FLOAT</code>,
 <code>DFLOAT</code>, <code>COMPLEX</code> and <code>DCMPLX</code> are treated alike.

    <p>As an extension, GNU Fortran allows hexadecimal BOZ literal constants to
 be specified using the <code>X</code> prefix, in addition to the standard
 <code>Z</code> prefix.  The BOZ literal can also be specified by adding a
 suffix to the string, for example, <code>Z'ABC'</code> and <code>'ABC'Z</code> are
 equivalent.

    <p>Furthermore, GNU Fortran allows using BOZ literal constants outside
 DATA statements and the four intrinsic functions allowed by Fortran 2003.
 In DATA statements, in direct assignments, where the right-hand side
 only contains a BOZ literal constant, and for old-style initializers of
 the form <code>integer i /o'0173'/</code>, the constant is transferred
 as if <code>TRANSFER</code> had been used; for <code>COMPLEX</code> numbers, only
 the real part is initialized unless <code>CMPLX</code> is used.  In all other
 cases, the BOZ literal constant is converted to an <code>INTEGER</code> value with
 the largest decimal representation.  This value is then converted
 numerically to the type and kind of the variable in question.
 (For instance, <code>real :: r = b'0000001' + 1</code> initializes <code>r</code>
 with <code>2.0</code>.) As different compilers implement the extension
 differently, one should be careful when doing bitwise initialization
 of non-integer variables.

    <p>Note that initializing an <code>INTEGER</code> variable with a statement such
 as <code>DATA i/Z'FFFFFFFF'/</code> will give an integer overflow error rather
 than the desired result of -1 when <code>i</code> is a 32-bit integer
 on a system that supports 64-bit integers.  The &lsquo;<samp><span class="samp">-fno-range-check</span></samp>&rsquo;
 option can be used as a workaround for legacy code that initializes
 integers in this manner.

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	<h4 class="subsection">6.1.9 BOZ literal constants</h4>

	<p><a name="index-BOZ-literal-constants-335"></a>
	Besides decimal constants, Fortran also supports binary (<code>b</code>),
	octal (<code>o</code>) and hexadecimal (<code>z</code>) integer constants. The
	syntax is: ‘<samp><span class="samp">prefix quote digits quote</span></samp>’, were the prefix is
	either <code>b</code>, <code>o</code> or <code>z</code>, quote is either <code>'</code> or
	<code>"</code> and the digits are for binary <code>0</code> or <code>1</code>, for
	octal between <code>0</code> and <code>7</code>, and for hexadecimal between
	<code>0</code> and <code>F</code>. (Example: <code>b'01011101'</code>.)

	<p>Up to Fortran 95, BOZ literals were only allowed to initialize
	integer variables in DATA statements. Since Fortran 2003 BOZ literals
	are also allowed as argument of <code>REAL</code>, <code>DBLE</code>, <code>INT</code>
	and <code>CMPLX</code>; the result is the same as if the integer BOZ
	literal had been converted by <code>TRANSFER</code> to, respectively,
	<code>real</code>, <code>double precision</code>, <code>integer</code> or <code>complex</code>.
	As GNU Fortran extension the intrinsic procedures <code>FLOAT</code>,
	<code>DFLOAT</code>, <code>COMPLEX</code> and <code>DCMPLX</code> are treated alike.

	<p>As an extension, GNU Fortran allows hexadecimal BOZ literal constants to
	be specified using the <code>X</code> prefix, in addition to the standard
	<code>Z</code> prefix. The BOZ literal can also be specified by adding a
	suffix to the string, for example, <code>Z'ABC'</code> and <code>'ABC'Z</code> are
	equivalent.

	<p>Furthermore, GNU Fortran allows using BOZ literal constants outside
	DATA statements and the four intrinsic functions allowed by Fortran 2003.
	In DATA statements, in direct assignments, where the right-hand side
	only contains a BOZ literal constant, and for old-style initializers of
	the form <code>integer i /o'0173'/</code>, the constant is transferred
	as if <code>TRANSFER</code> had been used; for <code>COMPLEX</code> numbers, only
	the real part is initialized unless <code>CMPLX</code> is used. In all other
	cases, the BOZ literal constant is converted to an <code>INTEGER</code> value with
	the largest decimal representation. This value is then converted
	numerically to the type and kind of the variable in question.
	(For instance, <code>real :: r = b'0000001' + 1</code> initializes <code>r</code>
	with <code>2.0</code>.) As different compilers implement the extension
	differently, one should be careful when doing bitwise initialization
	of non-integer variables.

	<p>Note that initializing an <code>INTEGER</code> variable with a statement such
	as <code>DATA i/Z'FFFFFFFF'/</code> will give an integer overflow error rather
	than the desired result of -1 when <code>i</code> is a 32-bit integer
	on a system that supports 64-bit integers. The ‘<samp><span class="samp">-fno-range-check</span></samp>’
	option can be used as a workaround for legacy code that initializes
	integers in this manner.

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