text: /**
  * @license Apache-2.0
  *
  * Copyright (c) 2018 The Stdlib Authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *    http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
  
  'use strict';
  
  // MODULES //
  
  var tape = require( 'tape' );
  var isnan = require( '@stdlib/math/base/assert/is-nan' );
  var randu = require( '@stdlib/random/base/randu' );
  var abs = require( '@stdlib/math/base/special/abs' );
  var expm1 = require( '@stdlib/math/base/special/expm1' );
  var ln = require( '@stdlib/math/base/special/ln' );
  var EPS = require( '@stdlib/constants/math/float64-eps' );
  var powm1 = require( './../lib' );
  
  
  // FIXTURES //
  
  var data = require( './fixtures/cpp/output.json' );
  
  
  // TESTS //
  
  tape( 'main export is a function', function test( t ) {
  	t.ok( true, __filename );
  	t.equal( typeof powm1, 'function', 'main export is a function' );
  	t.end();
  });
  
  tape( 'the function accepts two parameters: a base and an exponent', function test( t ) {
  	t.equal( powm1.length, 2, 'arity is 2' );
  	t.end();
  });
  
  tape( 'if provided an exponent equal to `0`, the function returns `0`', function test( t ) {
  	var i;
  	for ( i = -100; i < 100; i++ ) {
  		t.equal( powm1( i, 0.0 ), 0.0, 'returns -1' );
  		t.equal( powm1( ( randu()*10.0 ) - 5.0, 0.0 ), 0.0, 'returns 0' );
  	}
  	t.end();
  });
  
  tape( 'if provided a base equal to `0`, the function returns `-1` (except when the base is 0)', function test( t ) {
  	var i;
  	for ( i = -100; i < 100; i++ ) {
  		if ( i === 0 ) {
  			t.equal( powm1( 0.0, i ), 0.0, 'returns 0' );
  			continue;
  		}
  		t.equal( powm1( 0.0, i ), -1.0, 'returns -1' );
  		t.equal( powm1( 0.0, ( randu()*10.0 ) - 5.0 ), -1.0, 'returns -1' );
  	}
  	t.end();
  });
  
  tape( 'the function evaluates `bˣ - 1` (tested against Boost)', function test( t ) {
  	var expected;
  	var delta;
  	var tol;
  	var b;
  	var x;
  	var y;
  	var i;
  
  	b = data.b;
  	x = data.x;
  	expected = data.expected;
  
  	for ( i = 0; i < b.length; i++ ) {
  		y = powm1( b[ i ], x[ i ] );
  		delta = abs( y - expected[ i ] );
  		tol = 2.0 * EPS * abs( expected[ i ] );
  		t.ok( delta <= tol, 'within tolerance. b: ' + b[ i ] + 'x: ' + x[ i ] + '. actual: ' + y + '. E: ' + expected[ i ] + '. tol: ' + tol + '. Δ: ' + delta + '.' );
  	}
  	t.end();
  });
  
  tape( 'the function evaluates `bˣ - 1`', function test( t ) {
  	t.equal( powm1( 2.0, 3.0 ), 7.0, '2^3-1 = 7' );
  	t.equal( powm1( -5.0, 3.0 ), -126.0, '(-5)^3-1 = -126' );
  	t.equal( powm1( -5.0, 2.0 ), 24.0, '(-5)^2-1 = 24' );
  	t.equal( powm1( 1.0e6, 0.1 ), 2.9810717055349727, '1e6^0.1-1 ~ 2.981' );
  	t.end();
  });
  
  tape( 'the function evaluates `bˣ - 1` as expm1( ln(b) * x ) for sufficiently small b or x', function test( t ) {
  	var expected;
  	var actual;
  
  	expected = expm1( ln(4.0)*1.0e-3 );
  	actual = powm1( 4.0, 1.0e-3 );
  	t.equal( actual, expected, '4**(1e-3) = exp( ln(4)*1e-3 )' );
  
  	expected = expm1( ln(1.1)*0.4 );
  	actual = powm1( 1.1, 0.4 );
  	t.equal( actual, expected, '1.1**(0.4) = exp( ln(1.1)*0.4 )' );
  
  	t.end();
  });
  
  tape( 'the function returns `NaN` if provided a negative base and a exponent which is not an integer', function test( t ) {
  	var y;
  
  	y = powm1( -125.0, 1.0/3.0 );
  	t.equal( isnan( y ), true, 'returns NaN' );
  
  	y = powm1( -16.0, -0.5 );
  	t.equal( isnan( y ), true, 'returns NaN' );
  
  	y = powm1( -2.0, -1.25 );
  	t.equal( isnan( y ), true, 'returns NaN' );
  
  	t.end();
  });
  
  tape( 'the function returns `NaN` if provided a `NaN` for the exponent', function test( t ) {
  	var y = powm1( -3.0, NaN );
  	t.equal( isnan( y ), true, 'returns NaN' );
  	t.end();
  });
  
  tape( 'the function returns `NaN` if provided a `NaN` for the base', function test( t ) {
  	var y = powm1( NaN, 5.0 );
  	t.equal( isnan( y ), true, 'returns NaN' );
  	t.end();
  });
  