D std.random different behavior between integer and decimal uniform random number generation

I'm generating some seeded random numbers in D using the default random number generation engine, and I'm getting some "slightly off" values depending on whether I request integer or floating point/double random number generation. For example this code:

import std.random; // From docs: alias Random = MersenneTwisterEngine!(uint, 32, 624, 397, 31, 2567483615u, 11, 7, 2636928640u, 15, 4022730752u, 18).MersenneTwisterEngine;
int seed = 123;
Random genint = Random(seed);
Random gendouble = Random(seed);
foreach (i; 0..4) {
    writefln("rand[%d]: %d %f", i, uniform(0, 1000000, genint), uniform(0.0, 1000000.0, gendouble));
}

generates these results:

rand[0]: 696626 696469.187433
rand[1]: 713115 712955.321584
rand[2]: 286203 286139.338810
rand[3]: 428567 428470.925062

For some reason they're close but off by a noticeable amount. Is this expected behavior? I'm not completely familiar with the method being used to generate the numbers so I'm wondering what might be causing this to occur. Specifically, the reason I'm curious about this is I'm trying to port some D code to Objective-C, using the MTRandom library:

int seed = 123;
MTRandom *genint = [[MTRandom alloc] initWithSeed:seed];
MTRandom *gendouble = [[MTRandom alloc] initWithSeed:seed];
for (int i = 0; i < 4; i++) {
    NSLog(@"rand[%d]: %d %f", i, [genint randomUInt32From:0 to:1000000], [gendouble randomDoubleFrom:0.0 to:1000000.0]);
}

and I'm getting these results:

rand[0]: 696469 696469.187433
rand[1]: 712956 712955.321584
rand[2]: 286139 286139.338810
rand[3]: 428471 428470.925062

Identical for retrieving random doubles, but here the integer results are much closer.. though sometimes off by one! Is 712955.32 supposed to be rounded up to 712956 using this method of random generation? I just don't know...

What's the best way I can ensure that my seeded random integer generation is identical between D and Objective-C?