Error   7   error C2440: '=' : cannot convert from 'glm::detail::tvec3<glm::mediump_float>' to `'float'`

struct triangle
{
    glm::vec3 vertex0, vertex1, vertex2;

    triangle(glm::vec3 vert1, glm::vec3 vert2, glm::vec3 vert3)
    {
        vertex0 = vert1;
        vertex1 = vert2;
        vertex2 = vert3;
    }
};

struct triangleDistance
{
    float vertex0, vertex1, vertex2;
};

int sign(const double inputNumber)
{
    if (inputNumber >= 0) return 1;
    else return -1;
}

bool signIsTheSame(const triangleDistance inputDistance)
{
    return (sign(inputDistance.vertex0) == sign(inputDistance.vertex1) &&
        sign(inputDistance.vertex1) == sign(inputDistance.vertex2));
}

bool noneAreZero(const triangleDistance inputDistance)
{
    return (inputDistance.vertex0 == 0 || inputDistance.vertex1 == 0 || inputDistance.vertex2 == 0);
}

glm::vec3 computeTriangleNormal(const triangle inputTriangle)
{
    glm::vec3 crossTerm1, crossTerm2;
    return glm::normalize(glm::cross((inputTriangle.vertex1 - inputTriangle.vertex0),
        (inputTriangle.vertex2 - inputTriangle.vertex0)));
}

bool checkForCollision(const triangle triangle1, const triangle triangle2)
{
    glm::vec3 triangle2Normal = computeTriangleNormal(triangle2);
    glm::vec3 triangle2d = -triangle2Normal * triangle2.vertex0;

    triangleDistance triangle1Distance;

    triangle1Distance.vertex0 = glm::dot(triangle2Normal, triangle1.vertex0) + triangle2d;
    triangle1Distance.vertex1 = glm::dot(triangle2Normal, triangle1.vertex1) + triangle2d;
    triangle1Distance.vertex2 = glm::dot(triangle2Normal, triangle1.vertex2) + triangle2d;

    return (signIsTheSame(triangle1Distance) && noneAreZero(triangle1Distance));

    return false;
}